निर्मल (nirmal) - university of michigandesci501/2012/apd-2012-04.pdfmachines but the...

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निर्मल (Nirmal)

Anu Martikainen

Carrie Funk

Giannis Papazoglou

Ilias Anagnostopoulos-Politis

Siddharth Kale

Abstract

In developing countries like India, resources such as water and electricity are severely limited and expensive. These conditions along with the low earning potential of millions of people lead to severe problems associated with hygiene in the personal space. It is easy to criticize the poor for being unclean but when one is faced with such abject poverty, issues of hygiene are often neglected. We present a design of a product for underprivileged people in India to wash clothes while consuming minimal resources. This report addresses the need for such a product, its critical attributes and characteristics, existing competition, conceptual design generation and selection. We further describe the design parameters for the selected concept, its analysis and optimization while also exploring sustainability and lifecycle issues. Economic analysis and microeconomic modeling for the product have also been presented, which present a clear picture about the target market for such a product along with projected revenue for such a product.

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Table of Contents

Nomenclature ................................................................................................................................. 5

I. DESIGN PROBLEM DEFINITON ................................................................................................ 6

Motivation ................................................................................................................................... 6

Impact on the target consumer .................................................................................................. 6

Market of the proposed product ................................................................................................ 6

Laws and regulations in the design sphere ................................................................................. 7

II. DESIGN ATTRIBUTES AND CHARACTERISTICS ........................................................................ 7

Design problem statement ......................................................................................................... 7

Design attributes ......................................................................................................................... 7

Quality function deployment (QFD) matrix ................................................................................ 8

Design characteristics ................................................................................................................. 8

Design objectives and requirements .......................................................................................... 9

III. PREVIOUS DESIGNS ........................................................................................................... 10

Giradora .................................................................................................................................... 10

Upstream .................................................................................................................................. 10

Bicilavadora ............................................................................................................................... 11

The Wonder Wash .................................................................................................................... 11

Product positioning in the market ............................................................................................ 11

Business context ....................................................................................................................... 12

IV. CONCEPT GENERATION AND SELECTION ......................................................................... 12

Drum-in-drum concept ............................................................................................................. 12

Hand cranked machine concept ............................................................................................... 13

Gyroscope based concept ......................................................................................................... 13

Pendulum concept .................................................................................................................... 14

Telescopic agitator concept ...................................................................................................... 14

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Assembly line type concept ...................................................................................................... 14

Horizontal versus vertical axis designs ..................................................................................... 15

Design selection ........................................................................................................................ 16

V. CONCEPT PROTOYPES ........................................................................................................... 17

Alpha Prototype ........................................................................................................................ 17

Beta Prototype .......................................................................................................................... 17

CAD Model of Product Design .................................................................................................. 18

VI. ENGINEERING ANALYSIS ................................................................................................... 19

Objective ................................................................................................................................... 20

Optimization Constraints and Constants .................................................................................. 20

Optimization Engineering Analysis ........................................................................................... 20

Optimization Results ................................................................................................................. 21

Interpretation of results ........................................................................................................... 21

Proposed Wash Cycle ................................................................................................................ 21

VII. EMOTIONAL AND AESTHETISTICS ANALYSIS .................................................................... 22

VIII. ECONOMIC ANALYSIS ........................................................................................................ 23

Cost ........................................................................................................................................... 23

Variable Costs ........................................................................................................................... 23

Fixed Costs ................................................................................................................................ 25

Microeconomic Model .............................................................................................................. 25

Economic Objective .................................................................................................................. 27

Economic Optimization ............................................................................................................. 28

Variation in design results ........................................................................................................ 30

IX. MARKETING ANALYSIS ...................................................................................................... 30

X. SUSTAINABILTY ANALYSIS .................................................................................................... 33

XI. PRODUCT DEVELOPMENT PROCESS ................................................................................. 35

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XII. BROADER IMPACT ............................................................................................................. 36

XIII. CONCLUSION ..................................................................................................................... 37

REFERENCES .................................................................................................................................. 38

Appendix A: Additional Images of Giradora ................................................................................. 39

Appendix B: Additional Images of Upstream ................................................................................ 40

Appendix C: Typical Washing Machine Speeds ............................................................................ 41

Appendix D: Typical Washing Machine Torques .......................................................................... 42

Appendix E: First Gear Stage ......................................................................................................... 43

Appendix F: Engineering Design Optimization Excel Spreadsheet ............................................... 45

Appendix G: Bill of Materials ........................................................................................................ 46

Appendix H: Survey Response Data .............................................................................................. 47

Appendix I: Team Gannt Chart ...................................................................................................... 48

Appendix J: Washing Machine Torque-speed characteristics ...................................................... 49

Appendix L: CAD Model for Product Design ................................................................................. 52

Appendix M: NPV/Sensitivity Analysis .......................................................................................... 54

Appendix N: CBC Survey and Part Worths .................................................................................... 55

Appendix O: Conjoint Analysis-Maximum Demand ..................................................................... 56

Appendix P: Conjoint Analysis-Maximum Profit (w/o Engg. Constraint) ..................................... 57

Appendix Q: Conjoint Analysis-Maximum Profit (with Engg. Constraint) .................................... 58

Appendix Q: Linked Model............................................................................................................ 59

Appendix R: Life Cycle Analysis on SimaPro 7.3 ........................................................................... 60

Appendix S: Existing Patents ......................................................................................................... 62

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Nomenclature R = Washing tub radius (m)

ω1 = Angular velocity of the pedals (Rad/s)

ω4 = Angular velocity of the agitator shaft (Rad/s)

T1 = Torque input by the user via pedaling (Nm)

T4 = Torque output of the agitator shaft (Nm)

P1 = Power input by the user via pedaling (W)

P4 = Power output of the agitator shaft (W)

G1 = Pedaling gear ratio (unitless)

G2 = Bevel gear ratio (unitless)

H = Fill height of the washing tub (m)

Vtub = Occupied volume of washing tub (L)

Fdrag = Drag force on agitiator (N)

Tdrag = Torque resulting from drag on agitiator (Nm)

Iagitator = Moment of Inertia of agitiator (kgm2)

Re = Reynolds Number (unitless)

Cd = Drag coefficient (unitless)

N = Rotational speed (Radians per second)

V = Velocity (m/s)

ρwater = Density of water (kg/m3)

μwater = Dynamic viscosity of water (kg/ms)

A = Cross-sectional area of the agitator (m2)

D = Diameter (m)

α = angular acceleration (Rad/s2)

Pdrag = Power associated with drag force on the rotating agitator (W)

Q= Quantity of product

Cf = Fixed cost ($)

Cv = Variable cost ($)

Ctotal = Total cost ($)

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I. DESIGN PROBLEM DEFINITON

Motivation

Motivation for the project comes from being able to provide underprivileged people the ability to exercise hygiene in equal measure as the more fortunate people, while keeping the solution affordable, practical and accessible to them at the same time. The driving force behind the concept is to provide our target audience with a choice to improve their living conditions and give them a chance to make themselves cleaner, healthier and hence more productive citizens of the world.

The viewpoint assumed for decision making is that of a common citizen that fits our persona, which is discussed later in the report. We have tried to incorporate, through personal experiences and target audience surveys which would be conducted online, the most appropriate representation of the problems, needs and aspirations of the end user.

Impact on the target consumer

The successful completion of the design would ensure that the target consumer, underprivileged people in a country like India, would stand to gain out of the product. These people typically do not currently own a product to meet their hygiene requirements. This may be due to one or a combination of several reasons which include but are not limited to: inability to afford an expensive alternative, sporadic supply of electricity and water and suffering severe physical stress while doing similar chores manually. They still have a desire to improve their living standard; these are the kind of people who stand to benefit the most from this product.

Through the development of this product we aim to compete with leading consumer electronics manufactures who do provide solutions but are generally prohibitively expensive or our target audience. There is a small group within our target market that may purchase lower end models or even used machines but the persisting problem of resource scarcity still affects them. We intend to create a niche for our product by positioning it not only as a cheaper but also a more resource efficient option.

Market of the proposed product

If we consider a developing country like India as our target market, then according to World Bank estimates, about 30 % of its population lives below the national poverty line. Thus about 350 million people in the country are below the national poverty line. According to another report from the World Bank, approximately 42 % of the population is below the international poverty line of $1.25 per day. Further, 82 % of the population makes less than $2 per day, while almost 96 % percent of the population makes below $5 a day. As of 2011, India has a population of over 1240 million [6].

The vision for the customer is represented more accurately by the persona included on the next page. The purpose of defining a persona here is to add a human element to the design process. We believe it makes it easier for us as a team to develop a product when we have a face to connect to it.

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Figure 1: Persona

Kamla, 28, Married with 4 children, house-maid, Pune, Annual income $ 2200, only earning member of family, works 12 hours a day

The product is to be designed for people like Kamla, who may not necessarily be below the international or national poverty line but still earn well below $10 a day. Data from the World Bank also shows that almost 95 % of India’s population earns less than $5 per day, extending the same numbers we are still looking at close to 200 million people earning between $2 and $5 per day. These people are not technically below the poverty line but can be considered underprivileged when compared to an average American earning about $125 per day.

Our typical user group could include a host of people with traditionally lower paying jobs such as daily wage earners, laborers, maids, drivers, mechanics etc. This is the customer profile we are targeting, as they are above the poverty line technically but still poor enough to be unable to afford more expensive options.

Laws and regulations in the design sphere

Since the idea is to develop a product which is in the typical consumer appliance sphere, we are not aware of any laws or regulations which may be prohibitive to the entry of our product in the market. Since the aim is to make a product that ideally does not need electrical supply even regulations such as the ones pertaining to electrical or fire safety do not arise.

II. DESIGN ATTRIBUTES AND CHARACTERISTICS

Design problem statement

Our team aims to design a product for underprivileged people in India with no or limited access to electricity to be used for laundry washing while minimizing physical effort.

Design attributes

In order to define our design attributes we must consider the functionality of our product and the target market in which we intend to sell our product.

Distilling design priorities from our design statement we concluded that our product should be inexpensive, since the income of the potential buyer is low. It must also be easy to use since a majority

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of the target audience may not be highly educated and would tend to be technologically handicapped, hence the product operation and maintenance should not be complex. As far as possible it should be ergonomically designed and should need minimal input from the user.

Durability of the product is another important aspect since this will save the costumers from replacement or maintenance related costs and downtime. Even if it needs repairs it must be easily repairable, and spare parts should be available easily and those should be easy to assemble.

Another important criterion we must keep in mind is the energy and recourse efficiency of the product since our target market is developing countries the energy and water consumption is important, not only economically but due to acute shortage and sporadic availability. Nevertheless the functionality of the product must not be sacrificed in order to make it cheaper or more eco-friendly and the design must prove better than the existing method which is predominantly washing by hand.

Finally the final product must be aesthetically pleasing and ergonomic in its use. User fatigue is a problem we are aware of and would want to minimize it as much as possible by means of our product design.

Quality function deployment (QFD) matrix

Att

rib

ute

s

Characteristics

chea

p

ergo

no

mic

op

erat

ion

tim

e

colo

r

shap

e

wei

ght

and

siz

e

stu

rdy

sust

ain

able

mat

eria

ls

ener

gy e

ffic

ien

t

inexpencive x x

easy to use x x x x

add value to peoples lives x x x x x

safe to use x x x

long lasting x x

repairable x x x x

efficient x x x

functional x x

transportable x x

attractive x x x x x

cleanliness x x x

easy to maintain x x x x

not noisy x

reliable x x

large capacity x x x x

Table 1: QFD Matrix

Design characteristics

Characteristics are the technical aspects which can be worked upon by the designer to make the product conform to the attributes that are desirable to the user. Thus, along with our product’s attributes we have to define its characteristics and the ways that we will use to measure them.

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- Inexpensive, our product should be inexpensive so that people with low incomes can actually purchase the product. In order to measure if our product’s cost is low enough, we can benchmark it against existing competition and also by analyzing the monthly income ad purchasing power of our target user.

- Capacity, it should be sufficient to wash an average load of 8-10 clothing items per load. This data is based on surveys regarding the number of clothing items washed daily for a family of 4 in India.

- Water usage, minimal use of water is desired. This is related to the capacity of the machine.

- Ergonomic, it must be ergonomic, easy and comfortable to use. This can be measured by analyzing dimensions of the product and performing an ergonomic study.

- Operation time, product should be time efficient, this can be measured by time required for the cleaning cycle.

- Color and shape, affects the attractiveness of the product, if the product is attractive the potential user will more likely buy the product and have a positive image of the product, survey to the potential buyers and exposure of our product to the market will give a metric in this area.

- Weight and size, affects the transportability of the product, product should be carried by a person comfortably. The average human lifting capacity compared to the product’s net weight can provide a good metric.

- Sturdiness, affects the life of the product. Stress analysis of the key parts and joints in the product and its comparison with standard loads experienced during the product’s operation can provide this information.

-Energy efficient, making the product so that it needs fewer resources to operate, this adds more value to the people’s lives. Reducing the washing cycle time will result in less operating energy and water consumed per washing load.

Design objectives and requirements

We plan to ensure ease of use by keeping the effort required to drive the machine within widely accepted human strength data, for a short cycle time, and appropriate amount of water for washing clothes which would be a function of identifying the correct capacity of the machine to serve its intended use. All this should be achieved while ensuring the environmental impact of our product is low by ensuring we move people away from using rivers as primary sources of washing clothes, which is a huge source of pollution.

A successful final design will require the weight to be less than 50 kgs, with a maximum space envelope of 1.5m x 1.0m x 0.5m. We intend to keep the cost below $50 per family while ensuring that the cycle time is below 40 minutes.

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III. PREVIOUS DESIGNS There are many existing solutions for affordable washing of clothes in developing countries, each with their advantages and limitations. This section outlines four of products which function without the use of electricity, the existing patents and the design gap we are trying to bridge.

Name Cost ($)

Power Type Cycle Time (min)

Materials Used Capacity Patents

Giradora[1][2][3] ~40 Spring-loaded foot pedal

45 Plastic, metal shaft ~ 10 liters

Pending

Upstream[3][4] 4 Pedal-rope - Plastic bucket, plastic fiber rope, old water pipes, neoprene cover

~ 19 liters

-

Bicilavadora[3][5] 160 Bike-pedaling 45 Plastic barrels, bicycle components

~ 58 liters, 5lb

-

Wonder Wash[3]

43 Hand-crank

Less than 5 min

Plastic ~ 22 liters, 5lb

Not found

Table 2: Comparison of existing solutions

Giradora

Although it is more ergonomic than scrubbing by hand clothing while bent over, the Giradora, shown in Figure 2, requires foot stomping to power the washing as is visible in the picture above. The portable plastic tub can be filled with soap and water before a lid is placed on top, acting as a seat. Then the user needs to sit on the washer, and pump the spring-loaded foot pedal. This seems quite tiring mainly because it requires 45 minutes of repetitive foot stomping to do one small load of wash. This product, however, is very affordable at only $40. More images of the Giradora can be seen in Appendix A.

Upstream

Upstream, shown below in Figure 3, was the cheapest product we found at only $4, however, it is not ergonomic or sturdy. The machine needs to be mounted into the ground, making it difficult to set up in certain environments such as gravel, rocky areas, or cement. A positive aspect of its design is the fact that it can be disassembled and all of the parts may be stored within the bucket. A 5-gallon bucket, a plastic fiber rope, old water pipes, and a neoprene cover are required. The human-powered machine is assembled with the neoprene cover acting as a stain remover. The user then fills the

Figure 2: The Giradora

Figure 3: Upstream

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bucket with clothes, detergent and a little water before closing the cover of the bucket. Two loops of the plastic rope are then strapped onto their feet which they move up and down to rotate the bucket. However lack of proper support while moving feet up and town may be tiresome. More images of Upstream can be seen in Appendix B.

Bicilavadora

The Bicilavadora, shown above in Figure 4, is simple and ergonomic to operate but not portable. It uses a modified oil drum as its primary wash volume, a mountain bike frame with gearing mechanism to drive the machine. Changing gears causes the speed to change thus alternating the wash and spin cycles. It is however an expensive proposition with an estimated cost of $160 and no mention of whether it will be positioned as a community washer.

The Wonder Wash

The Wonder Wash, also shown in Figure 5, costs about the same as the Giradora, but has a much smaller capacity. It is small and portable and has a very short cycle time. It works with hand cranking wherein the entire drum tumbles around as it cranked. Unfortunately, there are no readily available parts if the machine breaks since it is not composed of commonly used elements. It also has a patented pressure development system which may make it difficult to repair, since no details of its construction are readily available. Another advantage of both the Bicilavadora and the Upstream is the availability of parts for repair from common sources. These are easier to make close to where they will be used, reducing the final cost of the product.

Product positioning in the market

To demonstrate our intended market niche, Figure 6 below illustrates the existing competition’s positions in the market space with respect to cost and capacity as well as our own. There are four main competitors to our product, but none of these products are currently readily available in India. Our product will differ from the main competitors because we are planning to design and build a washing machine to be used and owned by a community. We understand and value the importance of family and community in this market and would like our product to support it. Community ownership will require a more durable product to withstand frequent use. Because of this, our product will likely cost more than the products that are meant to be used by only one user. Our product will have a much larger capacity than the Upstream, Giradora, and Wonder Wash, and be similar to that of the Bicilavadora. We expect the price of our product to be similar to or more expensive than the Bicilavadora. However, being a community purchase, the price per family would be below that of Bicilavadora.

Figure 4: Bicilavadora

Figure 5: The Wonder Wash

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Figure 6. Product positioning chart and our intended market niche

Business context

To clarify the business context of our design problem, this section explains our intender user, customer,

and producer. The intender user of our product is someone similar to the persona as detailed earlier in

the report; a low income woman with a large family in India. Our customer who purchases the product,

however, is not the user. Our intention is to sell the product to a non-profit organization (Red Cross,

UNICEF etc.) and/or the Government of India. We would outsource the manufacturing of our design to a

local manufacturer in India, which would reduce manufacturing costs drastically and use the

government’s preexisting network and distribution resources to get our product to our intended users.

This approach will also minimize logistical costs.

IV. CONCEPT GENERATION AND SELECTION Using techniques such as brainstorming, morphological analysis and the 77 cards on design heuristics we came up with many design ideas during the ideation stage. These designs are evaluated with respect to the design characteristics and attributes set by the team earlier, leading to the most promising design concept from among all contenders.

Drum-in-drum concept

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Figure 8: Drum-in-drum concept

The concept behind this particular design was to use a drum-in-drum arrangement to improve the contact area between clothes and the washing surface. A concentric drum arrangement also gives the option of putting dirtier clothes in the center between the agitator and first drum as they would get scrubbed thoroughly due to the agitator also making contact. The delicate and comparatively less dirty clothes can go between the two drums. The argument was that this particular arrangement would also save water since it would clean better so the job would be done faster. This arrangement would have a horizontal axis. This idea although novel posed problems with fabricating the actual device in the allotted time and since cost and ease of use are major considerations in our design, it was thought that this would increase the cost and complexity.

Hand cranked machine concept

Figure 9: Hand cranked machine concept

An idea was also put forth wherein the entire machine would just be the bucket with a rotary hand cranking lever at its top. The operator would then manually rotate the lever to directly provide motion to the agitator. Fatigue associated with prolonged hand cranking was the main issue with this idea.

Gyroscope based concept

Figure 10: Gyroscope based concept

Use of a gyroscope based machine with the premise that the machine acts as a complete capsule type of unit which will be set on the spin axis and motion provided to the gimbal was also explored. The apparatus would receive input in the form of pedaling by the operator. The motion along this axis along with the fact that the spin axis is free to rotate on its own would impart a tumbling motion in 3 dimensions to the washing capsule. Complicated plumbing to ensure the machine gets water supply and the size of a gyroscope needed to execute such a motion on a machine were the major concerns.

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Pendulum concept

One method involved the use of a hand cranking lever to provide actuation to a dynamically balanced mass which would then acts as a pendulum and via a cam mechanism would provide an up-down motion to the agitator instead of the traditional rotary motion. Problems associated with balancing the mass properly as well as increasing the overall mass of the system due to the nature of the heavy pendulum were hindrances. Although a promising concept, the fact that balancing such a system involves technical expertise which not always be available at site where we intend to supply the product were also major concerns.

Telescopic agitator concept

Figure 11: Telescopic agitator concept with rotor at end

An idea related to making the agitator out of a telescopic beam so that its length is adjustable was also floated. The motivation behind a rotor based agitator with an adjustable length was to make its length adjustable so that it could be adapted to different sizes of buckets and make it easier to store after use.

Assembly line type concept

Figure 12: Assembly line type concept

The possibility of using something on the lines of a press assembly line was also in consideration. Clothes would be laid on a perforated table and water stored atop in a chamber with a piston would be forced onto the clothes under pressure, pass through them and collect in the bottom reservoir. Complications in operation and maintenance of such a machine were deemed to exceed its value for our target customer.

Another major concept involved the use of a bucket as the washing drum and there were several ideas which that revolved around this central theme and about how to provide it motion. This idea was carried forward to our most promising concept.

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Another design used the same ‘bucket as drum’ concept and provided rotary motion to the agitator by means of a wind powered turbine. A problem faced by such wind based actuation is the fact that wind in itself is very sporadic and it cannot be relied upon. Using a winding spring and solar power were some other suggestions regarding powering the machine.

The agitator is a central theme in a lot of these concepts. Conventional washer having a rotationally oscillating agitator relies on upon the production of a toroidal circulation and agitation of the combined mass of the clothes and water as a whole with incidental and accidental scrubbing of clothes by agitator blades.[7]

There are mainly two types of agitator designs which are most commonly used in washing machines. The first types are straight vane agitators which are common on most top loading washing machines. These agitators consist of a single piece of molded plastic fit over the agitator hub. Vanes project from the side of the agitator. The entire agitator spins inside the washing machine tub, providing the cleaning action for the clothes inside. These types of agitators sometimes have problems with circulating the clothes that float near the top of the wash.

Another type is the dual action agitator which is similar to straight vane agitators, but more efficient. Instead of a single piece of plastic, the dual action agitators are formed of two different pieces of plastic, a top piece and a larger bottom piece. The purpose of the top piece is to help circulate the clothes floating on the surface of the water in the washer and force them down toward the larger fins at the bottom so the clothes inside the washer tub circulate not only in a circular motion but also between the upper and lower levels of the wash chamber.[8]

Horizontal versus vertical axis designs

There are two main types of washing machines in the market;, top-loaded and front-loaded washing machines. Typical American washing machines are vertical axis machines which consist of two piece vertical axis agitator. The agitator forces clothes back and forth through water in order to clean the clothes. In front-loaded washing machines, also called horizontal-axis washing machines, there is no agitator but instead, the whole tub cycles horizontally which causes the clothes to be lifted out and plunged back through the water.

Figure 13: Vertical (left) versus horizontal axis (right) washing machines.

Front-loaded washing machines have several advantages over their top-loaded rivals. Front loading machines can save a lot of energy and water and can also prolong the life of the clothes washed in them. However, even though horizontal axis washing machines have many advantages, for our product we decided to choose the top-loaded vertical washing machine for several reasons. Because in our design the machine gets its power mechanically by cycling, the vertical axis bucket is sturdier because only the

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agitator inside the bucket is moving and not the whole bucket as in horizontal washing machines it would do. This way the vertical axis bucket is also easier to support with support shafts. The capacity of the washing machine was also a very important design criterion in our product. By using the vertical axis agitator, the cycling process is lighter because the cyclist doesn’t have to rotate the whole bucket. In order to have a larger capacity for our washing machine, we decided to use the vertical axis bucket and agitator. Top-loaded vertical axis washing machines are also usually easier and more ergonomic to load.

Design selection

Figure 14: Most promising design concept

The design that was considered the most promising is the one wherein we use a bucket/drum as the wash volume and use pedal powered actuation for the agitator. The user would sit on a seat which would be part of a skid mounted assembly which would contain the entire setup. Pedaling motion is transmitted via chain and sprocket arrangement, a rotary motion to the horizontal shaft. The rotation of the horizontal shaft gets transmitted to the vertical shaft by means of a bevel gear assembly.

There are concerns regarding the safety of users due to a long chain, we intend to provide a chain cover to mitigate such risks. Selection of gear ratios for pedaling which minimize effort is a top priority for the design, keeping in mind the target user of the product. As per initial CAD models the entire assembly should not exceed 40 inches in height, 25 inches in width and about 60 inches in length. Keeping in mind that the product is to be positioned as a community purchase the size seems to be alright. The major motivation behind selection of this design is that it scores heavily in the area of modularity, reparability-due to its simple mechanism and durability due to its metal construction which is essential for the trying conditions in which we envisage the product to perform in.

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V. CONCEPT PROTOYPES

Alpha Prototype

Based on the most promising concept, the team constructed a depiction of the concept as its alpha prototype (See Fig. 15, pg. 17). Commonly found materials such as plastic cups, straws, drain cleaners, Mechano set and clay were used to demonstrate the concept. Although out of scale, based on the feedback received from fellow class members, the alpha prototype did a good job to showcase the concept to the audience. We have taken some key learning’s from the alpha prototype into the Beta stage. Mainly placement and orientation of the cycling mechanism, size of the machine and the method to provide the structure required support were figured out on the basis of the alpha prototype.

Figure 15: Alpha Prototype

Beta Prototype

To demonstrate the functionality of our product design, we have constructed the Beta prototype shown in Figure 16. The prototype is to scale and full scale. Due to constraints on time and cost, our prototype is made from different materials than our final product. The prototype frame is made from wood, but our product will have a welded steel frame. Also, the gears in our prototype are made from Nylon, whereas the product will include still gears.

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Figure 16: Beta Prototype

CAD Model of Product Design

The CAD model of our product design is shown in Figure 17 below and in Appendix L. We use a steel welded frame in order to support our mechanism. In our design we followed the golden ratio, in the form of the golden rectangle in which the ratio between the longer and the shorter side is the golden ratio. This is in order to make our product more aesthetically pleasing. The dimensions we picked are 28 inches in height and width and 45, 36 inches in length. Also those dimensions were chosen so that we can make our product as compact as possible with respect to the bucket’s capacity.

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Figure 17: CAD Model for Product Design

Our driving mechanism consists from a bike crank set with pedals and is used as the power input. It is transferred to a horizontal shaft with a standard ANSI 40 (1/2’’ pitch) steel finished-bore sprocket with the use of a roller chain. A bevel gears pair is used to achieve the vertical rotation we need. Finally this rotating move is transferred to our agitator through the vertical shaft. The overall gear ratio used between input and output power is 1.6 as found from our optimization problem.

The horizontal shaft is supported by a pair of self-aligning steel flange-mounted needle roller bearings. Those are directly mounted on the frame.

Additionally, we are using a pair of horizontal supports for the vertical shaft in order to eliminate any movement and have the bevel gears and the agitator perfectly aligned. In each of these supports we use sleeve bearings to support the radial loads. On the second support we use a combination of a needle thrust bearing with two thrust washers to support the axial loads. On this point we also use a shaft collar to transfer the axial loads to the thrust bearing.

VI. ENGINEERING ANALYSIS In order to translate our design concept into a physical embodiment, our team had many decisions to make, many of them made arbitrarily in the interest of time. For our final product’s design, however, these decisions must be made via an optimization goal. By determining this optimization objective, defining relevant constraints, constants and equations, and using Excel solver, we were able to make key decisions to allow us to progress further in the design process.

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Objective

Our design represents a fairly simple process by which input force via pedaling is transformed into output via the agitator spinning in our bucket; therefore, we looked at two possible optimizations: Minimizing the rotational speed of pedaling or maximizing the rotational speed of the agitator. Given it is unreasonable to expect precision from a human-powered element such as pedaling, we instead decided to opt for assuming an average input of 60 rpm and optimize our design around the rotational speed of the agitator (ω4).

Optimization Constraints and Constants

Excel solver was used to find the optimized engineering design attributes. The constraints and constants are as shown below in Table 3. Table 3: Constraints and constants for Engineering Design Optimization

P1 (Input Power) <= 50 W Biomechanics data for 30 min. of women & children pedaling [9] T1 (Input Torque) <= 5 Nm Human torque limit for ease of use and low fatigue T4 (Output Torque) >= 2.5 Nm Minimum requirement for sufficient cleaning [10] G1 (Pedal gear ratio) >= 0 - Must be positive G1 (Pedal gear ratio) <= 1 - Maximum before effort to pedal increases G2 (Bevel gear ratio) >= 0 - Must be positive G2 (Bevel gear ratio) <= 3 - Maintains size of gears to reasonable level H (Water height) H (Water height)

<= >=

0.70 0.25

m m

Assumed max height of agitator Minimum height, corresponds to a small load of 3.5kg clothes

ω4 (Agitator angular velocity)

>= 4.18 Rad/s Minimum requirement for sufficient cleaning (corresponding to 40rpm) [10]

ω4 (Agitator angular velocity)

<= 10 Rad/s Maximum requirement for machine balance (corresponding to 95rpm)

R (Bucket/agitator radius)

= .175 m Radius of the bucket such that the agitator fits comfortably

ω1(Pedaling angular velocity) t (cycle time)

= <=

6.28 40

Rad/s min

Corresponds to 60rpm Maximum cycle time as per our design objective

Optimization Engineering Analysis

The capacity (V) of our bucket and the torque input by the user (T1) are determined by Equations 1 and 2 below, respectively.

21000V R h (Eq 1.) 1 1 1/T P w (Eq 2.)

We assumed a 10% loss in efficiency of our gears and chain due to friction. Based on this assumption, Equation 3 below gives the agitator angular velocity. Similarly, the power input (P1) is given as a function of the agitator’s angular velocity (w1), the output torque (T4), the gear ratios (g1,g2), and frictional losses.

4 1 1 2.9w w g g (Eq 3.) 1 41

1 2.9

wTP

g g (Eq 4.)

To determine the necessary torque output from the agitator, we considered the drag forces on the agitator. In order for the agitator to rotate at a constant speed (w1), we assumed Equation 5 to be true.

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Therefore, we can approximate the required torque as the torque from drag resistance. We estimated the drag coefficient based on the Reynolds number using Equations 6 and 7. As expected, the Reynold’s number indicates that the flow is fully turbulent. Using Equation 8, we estimated the drag force based on our calculated drag coefficient. From this, the power and torque resulting from the drag could be calculated. Equation 11 represents the substitution and reduction of all of these formulas, which was used in Excel solver. The relationship between the cycle time and the agitation rotation speed is given in Equation 11.

∑T = Iagitatorαagitator = 0 » T4 = Td (Eq. 5) Re = ρwaterND2/μwater (Eq. 6)

Cd = 0.4 for Re ~ 106 (Eq. 7) Fd = .5Cd ρwaterAV 2 (Eq. 8)

Pd = Fd V (Eq. 9) Td = Fd R (Eq. 10)

T = w41.63 (Eq. 11) 3

4 4400T hw R (Eq. 12)

Optimization Results

The optimization results for each of the variables and equations from Excel Solver are shown below in Table 4 and in further detail in Appendix E.

Table 4: Results of Engineering Design Optimization

G1 (Pedal gear ratio) 0.70 - G2 (Bevel gear ratio) 1.16 - H (Water height) 0.25 m ω4 (Agitator angular velocity) 4.66 Rad/s T1 (Input Torque) 3.37 Nm P1 (Input Power) 21.1 W T4 (Output Torque) T (cycle time)

2.5 22.0

Nm min

Interpretation of results

The above engineering optimization model considered boundary conditions as described in Appendix F. As is evident from the values shown above the engineering model had the boundary conditions on height of water (related to capacity) hitting its lower bound since the capacity is proportional to the effort needed to wash clothes and hence since effort was to be kept minimal this bound is reached in the optimization. Also, while the objective is maximizing the output angular velocity of the agitator, the input torque is constrained and hence keeps below the bound selected for the same.

Proposed Wash Cycle

Based on the literature surveyed, it is clear that when a machine manufacturer quotes a wash cycle time, it includes both the wash and rinse phases. It is observed that typically there is initially a soak phase, then wash phase followed by some soak time again which is generally half the time spent during wash phase. After washing again, the soapy water is drained off followed by two or three rinse cycles. This leads to the development of a step function of the wash cycle.

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Assuming a cycle length of about 29 minutes, which is what most machines claim as their base cycle, the following graph is obtained:

Figure 18. Sample Wash Cycle Profile

Obviously during the times the machine is OFF there would be no requirement for pedaling. So for a cycle of about 29 minutes, in effect the user will pedal only for 19 minutes. We propose to incorporate a timer in later iterations of the prototype to help users keep track of time.

VII. EMOTIONAL AND AESTHETISTICS ANALYSIS

Our main goal from an emotion and aesthetic perspective was to create a product which is memorable, simple, and inviting. Our product is unique in the Indian market, so we want our potential users to feel excited, yet at ease when they see the product for the first time. Visceral: The desired first impression of our product, Nirmal, should one of both unfamiliarity and familiarity. The product itself should seem new and exciting, yet the pedal-powered function of the design should be familiar and make the consumer feel at ease. The product will also look aesthetically pleasing as we have designed the overall size using the Golden Ratio. This will increase the likelihood of them purchasing the product since it will not seem too complicated to use. Behavioral: The product is very intuitive. Physically, the product is not very demanding as well. It is designed such that adolescents and old people are capable of operating it. This will elicit positive feelings from the consumer. Reflection: After the consumer uses the product he/ she will begin to reflect on the experience and compare it to his/her former methods of doing laundry. Since this product will save the user time and energy, the user will be satisfied. Also, some methods of wash require the user to bend over or sit in positions which are not ergonomic. Therefore, the user may experience relief from back pains.

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VIII. ECONOMIC ANALYSIS

Cost

Modeling the cost of the product is a key determinant of the economic success of a product. The cost of a product typically consists of the sum of variable costs and fixed costs, where variable costs are related to the volume of product produced. [11] The cost per product is approximated by Equation 13 below. The following sections outline our estimations for our fixed and variable costs.

Cproduct=CF/Q+CV (Eq. 13)

Variable Costs

Since our main target market is India, we decided to offshore the manufacturing in India. This way we can save a lot in labor cost and reduce shipping costs. Figure 19 shows the hourly compensation costs in manufacturing of different countries, in U.S. dollars, 2009. The hourly compensation cost is the average cost to employers of using one hour of labor in the manufacturing sector. Compensation includes payment for time worked, directly paid benefits and insurance and labor rated taxes. Figure 19 shows that even though in the recent years the labor costs in India have been increasing faster than those in U.S. the labor costs are still less than 4 % of the U.S level. Labor rates in India are estimated to be $1.34/hour. Since we are offshoring the manufacturing and assembly phase, the line workers’ wages are a variable cost. Upon surveying some workers from small scale companies it was found that the actual wages were closer to $0.60/hour for a semi-skilled worker in the urban centers.

However, we recognize that even though outsourcing can reduce the labor cost it can cause some

hidden costs, like for example concerning quality of the product and vendor selection. According to

Dewhurst and Meeker (2004), vendor selection cost is on an average around 1% of the product cost and

quality cost is on an average 4% of the product cost. Because we are selling our product to India,

outsourcing does not cause any extra shipping cost. Also, the materials for our product are easily

available in India, which is why the material cost is lower because of outsourcing. The hidden costs are

thus assumed to be 5% of the product cost. [12]

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Figure 19. Average hourly compensation costs in manufacturing in 2009 by nation.[13]

The outsourcing material and component costs of the product are shown in Appendix G. The material

costs are based on current Indian prices, also due to economics of scale the final cost per product is

estimated to drop by a further percentage. We envision the frame of the machine to be mass produced

by automated welding while the assembly of the components on to the frame would be done manually

at the plant. The total cost of the product is still difficult to estimate, since mass production of our

product and ordering components in bulk will reduce the cost per product significantly, as compared to

its current calculated cost.

Since we are outsourcing the manufacturing, we need to calculate a margin for the manufacturing

company. We are estimating that this margin would be 20% on the cost to produce the product. Since

we are the distributors who would be marketing the product along with detergent companies and

selling the product to non-profit organizations and Indian government we expect also to have 20%

margin. They are expected to have a 15% margin on top of that.

From the Bill of Materials, it is estimated that the cost of the materials going into the product would cost

close to $133. We assume that the manufacturing company would take into account any labor and

utility costs when it imparts the margin and sells the product to us. Also we have taken the prices of

components that go into just one unit, when the manufacturer makes thousands of units the cost of

materials and components would go down substantially since they would order them in bulk. Hence

assuming a margin of 20% over cost of materials (assuming one unit) should be sufficient to cover

labor/machining/utilities and a profit.

This cost is however, based on the production of just one machine, when economies of scale due to

mass production are applied to the same, we expect the price to drop down to about $60 per machine.

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This is again a conservative estimate based on production of about 20,000 machines in the first year.

This figure of 20,000 machines is based on the fact that we will be starting off with a pilot launch in the

state of Maharashtra. This will be elaborated in detail in subsequent sections.

The variable cost can be calculated from the equation:

Variable cost/unit = Cost of Manufacturing*Manufacturers margin=60*1.2= $72

Variable cost total (for the 1st year) = 250,000*Variable cost*units= $1,440,000

Fixed Costs

Since we plan to outsource the manufacturing and assembly of our product, the fixed cost contains only

salaries for employees over seeing the operation at producer’s end and engaging in sales coordination,

rent, marketing cost, insurance, and taxes. We are assuming that we don’t have to invest in tools or

equipment.

Table 5: Fixed costs for one year (in 1000s U.S. dollars)

Salaries (R&D, Marketing & Sales: 3 full-time, 2 part-time) Marketing (Website, Advertising) Office Rent and Utilities Testing (Pilot) Insurance Other (Computers, Printers, Travel Costs)

200 50 20

5 5

20

Total 300

The total cost of production is approximated as $1.74 Million from Equation 13 below. Therefore, the cost per one unit of production is approximately $72.

Ctotal= CF+CV*Q (Eq. 13)

This would be the cost at which we would acquire the product from our manufacturer. Adding a further 38% as our margin we would arrive at a value of $100. This would be the price at which we sell to NGO’s, Government or Detergent manufacturers. They would add 25% to this cost as their margin thus finally selling the product as $125 to the end user. This would work out to about $25 per family which is on track with our target and consumer willingness to pay as per survey results. The rationale behind selecting $125 as the price for the product is presented in the section on marketing analysis.

Microeconomic Model

There are no similar products in the Indian markets right now, so in order to make some kind of

assumption from our market share our group made a survey for Indian people. We were able to get

survey data from 19 people. These were people who are actually part of the demographic we are

targeting. Although the sample is small, we feel that it was more important to get information from

people who would actually buy our product than to get it from people who would be putting themselves

in their shoes to think about the survey responses.

Extrapolating this data to cover the target market size of 200 million people as discussed earlier in the

report, we estimate that the number of people who would be interested in buying our product would be

close 30 million. This is based on the fact that our survey revealed 75% people being interested in buying

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our product, while another 10% said they might consider it. The survey also revealed a mean family size

of 5 people amongst our target audience. Assuming each family to be one interested consumer we

arrive at the figure of 30 million.

We plan to position our product as a community purchase to reduce cost per family, and the survey

reveals that most people would want to share the unit between 3 to 5 families. This means one product

would be purchased between 4 families on average. This would mean that for the 30 million families

willing to buy the product, assuming a community size of 5 families, we would have a potential market

for about 6.0 million washing machines.

The market size mentioned above is the national market size and since we do not envision a national

launch in the immediate future, we will be starting out with a pilot launch in the state of Maharashtra

which account for roughly 9.5% of the national population. Thus if we extend these numbers in

accordance to the state’s population we arrive at a target market of close to 560,000 machines.

As of now there is no similar product which has been commercialized in the Indian market, and being

first movers and targeting an untapped market we are confident of dominating the market. We are

targeting potentially 20,000 users by the end of the first year in the first wave of sales, after this word of

mouth publicity, brand establishment combined with synergetic marketing with detergent

manufacturers would lead to an exponential growth over the next few years. By the time we have

targeted the initial chunk of first time buyers, we expect repeat orders to follow. However, over the

years with the introduction of this product as the market grows, we expect competition to enter the

market, which may lead to a dip in market share. Over time, as the market matures we hope to be able

to consolidate our position as a brand which people can trust. We have capped our analysis at the end

of year 5 by which time we expect to have captured close to 50% of the potential market in

Maharashtra.

Table 6: Five year prediction of market size and market share assuming an inflation of 7% in our price for years 2 through 5, keeping in trend the current Indian inflation figures. *Based on projected market size

Year Cumulative Products Sold (Thousands)*

Cumulative Revenue (Million $)*

Market Share (%)*

1 20 2 3.5

2 3 4 5

45 100 185 275

4.5 10 18.5 27.5

8 18 33 49

While considering the calculation for revenue generation we have considered the price we will get from

the retail end (NGO, Government and Detergent Manufacturers) and not the price at which the

consumer buys the product.

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Economic Objective

Based on the costs calculated above, we arrive at a total investment requirement for close to $1.1

million for the 1st year. This is based on the need for fixed costs at $300,000 annually as well as $720,000

which is cost incurred by us while purchasing 10,000 (demand for first 6 months) units from the

manufacturer. This is assumed as a cost since we are new players in the market and manufacturer may

not be willing to extend a line of credit to us initially. For the first 6 months we will pay him the price at

which he purchase from him, upfront, while we hope that after 6 months when we have developed a

good rapport and credibility with the manufacturer, he would extend a line of credit. Another $80,000

has been added as transportation costs incurred while distributing machines throughout the state from

our proposed facility in the city of Pune in Maharashtra.

Hence with a need for $1.1 million, a snapshot of our Net Present Value Analysis is presented below.

Figure 20. NPV spread and Break-even point

From the graph above we see a NPV of close to $2.1 million at the end of 5 years, this makes the project

a good investment since the initial investment was $1.1 million. It can also be seen from the graph that

the breakeven point arrives at the end of the third year.

While calculating the market size over the years we have assumed a steady population growth of about

1% annually, however, to be on the conservative side, we have not applied a similar growth percentage

to our demand. We have also accounted for an increase in the fixed costs over the years as inflation

creeps in.

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Figure 21. Sensitivity analysis of the NPV

The detailed excel sheet tabulating the results from the analysis are presented in Appendix M. This also

includes the sensitivity analysis.

Economic Optimization

Based on the demand projected and the willingness of the consumers to pay a certain price for the

product (derived from survey of target customer) we have been able to come up with the demand curve

for the product. Please note that in this figure the price is the price that a community would pay to

purchase the machine from the retailer and not what it would cost each family.

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Figure 22. Demand model.

Based on the demand model in Figure 22, using excel solver, the maximum profit model is obtained

below.

Figure 23. Profit Model

For economic optimization we have linked the cycle time as the engineering variable to the price that

people are willing to pay for the product, thus linking it to the demand. Cycle time is related inversely to

the agitator speed by an exponential relationship. Using this relationship and survey data from target

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users regarding their willingness to pedal (in minutes) and the price sensitivity, we were able to come up

with a price of $123 which would yield maximum profit. The consumer survey also adds a constraint on

the engineering model in the form of the cycle pedal time that is most desirable to maximum

percentage of consumers. It turns out to be about 17 minutes. The values of variables obtained are

shown in the Appendix K.

Variation in design results

We observe that there is a difference in the results of the design when we consider a purely engineering

model as expressed in the section on Engineering Analysis and the values we obtain when we link the

microeconomic model to the engineering parameters. This is an expected result since the initial

engineering analysis did not consider economic impacts and demand elasticity of product.

The major differences are seen in the values of the cycle time, in the engineering model we obtained a

cycle time of close to 22 minutes with gear ratios of 0.7 and 1.16, as it was aimed with providing

maximum output angular velocity with minimum input power needed.

However when the microeconomic model was incorporated into the scheme it got customer

preferences into the equation which link the cycle time with the price that customers are willing to pay

for the machine. This results in a cycle time of about 16 minutes and gear ratios of 0.45 and 2.56. This

will entail a change in the design of the gearing on the machine. A change in the design and capacity

(and hence material needed) of the machine is linked to the price of the machine.

IX. MARKETING ANALYSIS

In order to understand the market we conducted a conjoint analysis with data obtained from a survey conducted online. Participants included students from the class as well as some Indian friends of a team mate who were contacted through email and social networking. Through these means we were able to gather a participant pool of about 31 respondents. All the participants were quizzed on the importance they attach to key aspects of our product which included its price, cycle time and the capacity of clothes it could wash. The results from the survey and conjoint analysis were on expected lines with people opting for lower prices, higher capacities and small cycle times. The graphs below provide a graphical representation of part worths obtained from the CBC survey.

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Figure 24. Part worths from CBC Survey

Based on the part worths obtained from the CBC survey we were able to conduct a conjoint analysis to

determine the price of our product based on various scenarios which are tabulated as under:

Table 7: Comparison of prices for product as obtained from Conjoint Analysis

Maximize Demand

Maximize Profit (no Eng)

Maximize Profit (w/ Eng)

Qm 529604 459104 462398

Profit $27,873,474.15 $47,009,885.22 $46,934,255.71

Pedaling time (min) 15 15.00000011 15

Capacity (kg) 5.412715344 3.436796418 3.655499567

Price ($) 107 137 139

It can be observed from the table above that the maximum demand would be at the price of $107 which

is understandable since the demand is really elastic based on the price, the maximum demand scenario

also shows how consumers attach importance to capacity and a low cycle time. Since we considered a

lower bound of 15 minutes for cycle time, it is clear that it is important to consumers as it reaches its

lower bound.

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Apart from these three methods, when the demand elasticities were applied to create a new refined

microeconomic model based on the results from the conjoint analysis the following curve was obtained:

Figure 25. New Refined Microeconomic Model

From the new refined microeconomic model it is seen that profit is maximized for a price of $169 when

the demand elasticities are used in the governing equations. This is clearly a much higher price than

what the customer would be willing to pay for a sustained high demand.

From the combination of all these analysis we obtained a price spread between $107 and $169 which is

very wide and presents very contrasting scenarios.

Impact on design metrics

As compared to the earlier model it is very clear in the new model that the design parameters are

impacted by the importance that consumers attach to cycle time and capcity. This Is reflected by the

change in gear ratios needed to obtain such cycle times as well the change in height of the wash water

column and hence the machine as the demand for capacity changes. A need for lower cycle times results

in higher gear ratios to increase the agitator angular velocity while the capcity requirement leads to a

change in the height of the water column, hence size of bucket and frame as the capacity changes. In

order to accommodate the need for different demands, in our design, we have accounted for the

maximum capacity scenario wherein users with a demand for lower capacity can simply reduce the

amount of water they put into the machine in proportion to the load of clothes they wish to wash. The

full extent of these changes can be seen in Appendix Q which computes the data needed for plotting the

new microeconomic model.

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Rationale behind price selection

Looking over the price spread and the fact that the repondents who took the CBC survey are either not

from the target market or from the target income group, the team decided to attach more importance

to the price that the target consumer was willing to pay. Based on the earlier microeconomic model that

showed a maximum profit for $123, we decided to go with a price of $125 for the final product.

This price while being sufficientyl profitable also falls between the range provided by the Conjoint

Analysis and is able to strike a balance between high demand and profit, while being affordable and

desirable to our target consumer.

X. SUSTAINABILTY ANALYSIS

The assembly created in Solidworks for the model of our product was used as the basis for performing a life cycle analysis of our product. Commonly used materials for components we used as well as industry standard processes that go into the production were considered as part of an extensive life cycle analysis that was carried out in SimaPro 7.3.

The stack up of environmental damages across various stressor categories is shown using the Eco Indicator-99 metric.

Figure 26. Eco Indicator 99 (H) Nirmal Lifecycle Weighted Metrics

As is evident from the plot the maximum impact is observed in the fossil fuel category which arises due to the fact that shipping of components to our manufacturing location in Pune and the transport of finished goods throughout the state would done through trucks, which causes huge emissions.

Since we are using steel as the preliminary material for construction and about 20% of it can be recycled, it reduces our End of Life impacts as is shown by the green columns.

34

A study conducted by Loughborough University [14] claims that the production phase of a washing machine contributes to only 20% of its Lifecycle impacts while the use phase accounts for almost 80%. Our machine has no significant use phase associated with it, since it does not use electricity, which is the dominant stressor in the use phase, our product makes a very convincing case for its Lifecycle benefits. The production phase also would be far less environmentally harmful due to lack of any complicated electronic circuitry needed to manufacture the machine, since electronics use some of the most toxic chemicals for the manufacture of circuits and their disposal is also an issue.

A more detailed representation of metrics on normalized and composite scales, as well as the network of processes considered is presented in Appendix R.

We envision the following distribution of environmental impacts for our product’s different stages:

Product innovation:

This stage will add value to the environment by making use of existing buckets in households as the primary vessel for washing of clothes.

Low Impact Material use: Use of steel as the material for frame of the machine may have an adverse impact on the environment due to associated processes during its extraction and manufacturing. Similarly metals going into the gearing assembly may have an impact. However, the longevity of steel for same functional life offsets some of this impact.

Product manufacturing:

Use of commonly available materials will reduce manufacturing footprint, since custom production of parts would not be needed. Standard tooling and associated consumables will have to be accounted for.

Distribution system:

Manufacturing locally in India will lead to reduced transportation impacts as compared to sending finished product from the US. Nesting of the product assembly and therefore its packaging will also reduce impact. Producing the machine in Pune and distributing locally throughout Maharashtra keeps transportation distances low.

Minimize impact from use:

Use of detergents and lubricants during the use phase will add an environmental burden. Reduction in cycle time will reduce consumption of water.

Initial lifetime:

Making the product repairable will reduce impact on initial lifetime. Some component such as gear assembly, chains and sprockets may break and need to be replaced. Their disposal poses an environmental challenge.

End of life:

Since most parts used in the product would be metal or plastic based, their end of life is an issue. While metals may be reclaimed, certain plastic components may need to land filled.

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Figure 27: LiDS Wheel

XI. PRODUCT DEVELOPMENT PROCESS

After looking back at the APD course individual assignments on product development process diagrams and thinking about the design process of our Nirmal product, we came up with the product development process of the Nirmal washing machine, which is illustrated in the figure 28. During the semester we noticed that the product development process is really iterative and that is why it is hard to predict forehand the specific schedule of the design process.

36

Figure 28. Product development process of Nirmal wash machine.

XII. BROADER IMPACT Looking back and reflecting on how we got together as a team in the first place, we realized that there were a few themes across all our beliefs and motivations, reflected in our DDW essays, which linked all of us as a team. These themes were:

Love for nature and the environment

Focus on renewable/alternate energy

User centric and comfortable design

Engaging a sense of community in the society

It was indeed surprising to see how these beliefs that everyone held onto, have actually made a very significant impact on our product Nirmal. The fact that it is a product that is eco-friendly by means of lower resource consumption, is operated by pedaling which is independent of fossil fuels or need for electricity and finally is a product that can provide service to a community of people with varying needs while ensuring comfort over conventional manual washing is a triumph in the sense that unknowingly we have all addressed our motivations for doing such a project! We all have left an indelible mark of our motivations on the product, thus making the entire process thoroughly satisfying.

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XIII. CONCLUSION

As part of this project we were able to develop a pedal powered washing machine for underprivileged people in India. The developed prototype Nirmal, is capable of washing upto 6kg of clothes with a pedal time of just 19 minutes, for an overall cycle time of 29 minutes. The pedaling requires minimum effort due to optimized gear ratios for minimal effort, while ensuring fast cycle times. Based on economic analysis, it was decided to price the product at $125 to target a community of 5 families, in the state of Maharashtra, initially as a pilot launch. Some key decisions were made while selecting the design to pursue. The decision to go in with a top loading machine with a vertical agitator was made keeping in mind the ease of loading, operating, designing and repairing such a configuration. Pedal power was selected due to the ease to implement such a mechanism and target user’s familiarity with such a mechanism. Finally another critical decision was to go in with a bucket instead of designing a special drum for the machine, since this enabled different families to use their own buckets, as well helped reduce unnecessary costs. Over the course of this project we learnt several things about designing a washing machine, their characteristics and comparison between different configurations. We gained a deeper understanding about the nature of the Indian market and the extent of price sensitivity in the minds of the consumers. We learnt how to balance tight budgetary pressure while providing a quality design that would fulfill needs of the consumer. We were also in a position to identify limitations of our project. Some of the key limitations were: relationship between cycle time and capacity was established empirically and through discussion with people from relevant field but were not validated and hence cannot be completely accurate due to non-disclosure of such information by concerned companies; the washing machine has been over designed in some key areas which can be optimized further to reduce costs further; all market studies are within bounds of the people we have spoken to and may not be a true reflection of what an entire nation thinks about the product; while we have been conservative in estimating profits there is no surety about those figures and finally the design would have to be tested in the real world to identify possible design shortcoming which hasn’t been done. Future work for the project could include the possibility of exploring use of variable gear drive mechanism, designing a chair that is suited for our product to be sold as an optional accessory, relooking some of the mechanical components that have been used for the machine and exploring alternatives which would give a better service life for equivalent prices.

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REFERENCES [1] http://www.designboom.com/weblog/cat/8/view/22826/giradora-foot-powered-washer-and-spin-dryer.html

[2] http://inhabitat.com/human-powered-giradora-washer-needs-no-electricity-and-costs-only-40/

[3] http://www.homechunk.com/2858/2012/08/16/washing-machines-that-need-no-electricity-to-do-your-laundry/

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[9] http://books.google.com/books/about/Bicycling_Science_3rd_Edition.html?id=0JJo6DlF9iMC

[10] Marcetic et all, 2007, Application of Shaft-Sensorless Induction Motor Drive in a Washing Machine, 14th International Symposium on Power Electronics

[11]Ulrich, K., Eppinger, S. 2000. Product Design and Development. McGraw-Hill. USA

[12]Bureau of labor statistics. Available at: http://www.bls.gov/fls/chartbook/chartbook2011.pdf. Referred 02.11.2012

[13]Dewhurst, N., Meeker, D. 2004. Improved Product Design Practices Would Make U.S. Manufacturing More Cost Effective, A Case to Consider Before Outsourcing to China

[14] www.lboro.ac.uk/research/.../Life%20Cycle%20Assessment.ppt

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http://www.designboom.com/weblog/cat/8/view/22826/giradora-foot-powered-washer-and-spin-dryer.html

http://inhabitat.com/human-powered-giradora-washer-needs-no-electricity-and-costs-only-40/

http://www.homechunk.com/2858/2012/08/16/washing-machines-that-need-no-electricity-to-do-your-laundry/

http://www.homechunk.com/2858/2012/08/16/washing-machines-that-need-no-electricity-to-do-your-laundry/

https://www.engineeringforchange.org/news/2012/06/10/foot_powered_washing_machine_from_sketch_to_product.html

https://www.engineeringforchange.org/news/2012/06/10/foot_powered_washing_machine_from_sketch_to_product.html

http://web.mit.edu/newsoffice/2009/itw-bicilavadora-0219.html

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http://www.ehow.com/info_11414981_types-washing-machine-agitators.html

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http://www.lboro.ac.uk/research/.../Life%20Cycle%20Assessment.ppt

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Appendix A: Additional Images of Giradora

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Appendix B: Additional Images of Upstream

41

Appendix C: Typical Washing Machine Speeds

42

Appendix D: Typical Washing Machine Torques

43

Appendix E: First Gear Stage

45

Appendix F: Engineering Design Optimization Excel Spreadsheet

46

Appendix G: Bill of Materials Level Description Group Quantity Cost/Quantity Indian Prices in $

1 steel 1x1 frame 30ft 1.6 48

2 vertical shaft power transfer 23in 0.37 8.5

2 horizontal shaft power transfer 24in 0.37 9

2 flange mounted bearings power transfer 2 6 12

2 thrust bearings power transfer 1 2.5 2.5

2 thrust washers power transfer 2 2.25 4.5

2 sleeve bearings power transfer 2 2 4

2 crankshaft, pedals, sprocket

power transfer 1 3 3

2 sprocket 17 teeth power transfer 1 4 4

2 bevel gears power transfer 2 5 10

2 chain power transfer 6ft 0.6 3.6

3 agitator cleaning mechanism

1 20 20

3 bucket cleaning mechanism

1 4 4

Total Cost 133.1

47

Appendix H: Survey Response Data

Would you want to buy it?

Yes No Maybe

14 2 3

Willingness to pay

Upto $10 $15 $20 $25 $30 $30 and above

17 14 10 8 4 2

Capacity

Upto 2.5 kg 2.5 to 3.5 kg 3.5 to 4.5 kg 4.5-6 kg above 6 kg

3 2 5 6 1

Number of families with whom to share machine

Nil 1 to 2 2 to 3 3 to 4 4 to 5 more than 5

2 1 2 4 7 1

Number of people in family

less than 4 4 5 6 7 more than 7

1 4 6 3 2 1

Use per week

Once Twice Thrice Daily

0 2 4 11

Who will pedal

Men Women Children Elderly

1 7 7 2

Any space constraint for installing model of designed size? (about 60*24*38 inches)

Yes No

2 15

How long would you be willing to pedal the machine?

5-10 mins 10-15 mins 15-20 mins 20-25 mins More than 25 mins

4 5 7 1 0

Note: 6kg load generally means*

6 small towels

2 pillowcases

6 T-shirts

2 sheets

2 pairs of jeans

14 socks

46 liters water**

*http://www.which.co.uk/home-and-garden/laundry-and-cleaning/reviews/washing-machines/page/features-explained/

**http://www.very.co.uk/indesit-iwc6125-1200-spin-6kg-load-washing-machine---white/573896325.prd

48

Appendix I: Team Gannt Chart

Tim

elin

e, G

antt

Cha

rtw

eek 1

wee

k 2w

eek 3

wee

k 4w

eek 5

wee

k 6w

eek 7

wee

k 8w

eek 9

wee

k 10

wee

k 11

wee

k 12

wee

k 13

iden

tify n

eed/

prob

lem

pate

nt se

arch

and

exist

ing p

rodu

ct d

esig

n se

arch

brai

nsto

rmin

g and

sket

chin

g

QFD

mat

rix

Surv

ey d

esig

n

Desig

n pr

oble

m d

efin

ition

pro

gres

s rep

ort

defin

ing m

arke

t seg

men

tatio

n

conc

ept s

elec

tion

alph

a pro

toty

pe

CAD

mod

el

prop

osal

repo

rt

eval

uatio

n an

d ve

rifica

tion

of th

e al

pha p

roto

type

sele

ctio

n an

d pu

rcha

sing o

f mat

eria

ls an

d co

mpo

nent

s

engi

neer

ing a

naly

sis (f

unct

iona

lity)

colle

ct an

d an

alyz

e su

rvey

dat

a

econ

omic

anal

ysis

beta

pro

toty

pe

desig

n em

bodi

men

t pro

gres

s rep

ort

eval

uatio

n of

the

beta

pro

toty

pe

beta

+ pro

toty

pe

ergo

nom

ic st

udy

life-

cycle

anal

ysis

mar

ketin

g mod

el

build

ing a

bus

ines

s pla

n

final

repo

rt

Desig

natio

n

All

Ilias

Iann

isCa

rrie

Sidd

harth

Anu

49

Appendix J: Washing Machine Torque-speed characteristics

50

Appendix K: Economic Optimization Excel Solver Spreadsheet

Refined MicroEcon Model

Market Data for Similar Prodcuts

Price Quantity

Price 1 $50 560000

Price 2 $75 460000

Price 3 $100 395000

Price 4 $125 263000

Price 5 $150 131000

Price 6 $175 66000

New Part of Demand Function

Lamda_d1 Lamda_d2

-0.35

y = -4101.7x + 773943

0

100000

200000

300000

400000

500000

600000

$0 $20 $40 $60 $80 $100 $120 $140 $160 $180 $200

Dem

an

d

Price

Determine Elasticity

PQ

T

dpPQ

51

Ne

w D

em

an

d F

un

cti

on

En

gin

ee

rin

g M

od

el

Theta

Lam

da

Lam

da_d1

Lam

da_d2

773943

-4101.7

-0.3

50

Va

ria

ble

s

g1

0.4

55

Co

st

Fu

ncti

on

g2

2.5

6

Fix

ed C

ost

Variable

Cost

h0.2

5m

300,0

00.0

0$

60.0

0$

w

44.1

8ra

d/s

Co

nsta

nts

r0.1

75

m

Pri

ce

Qu

an

tity

Re

ve

nu

eC

osts

Pro

fit

w1

6.2

8ra

d/s

$0.0

0773942.6

637

$0.0

046,7

36,5

59.8

2$

($

46,7

36,5

59.8

2)

$10.0

0732925.6

637

$7,3

29,2

56.6

444,2

75,5

39.8

2$

($

36,9

46,2

83.1

9)

Eq

ua

tio

ns

$20.0

0691908.6

637

$13,8

38,1

73.2

741,8

14,5

19.8

2$

($

27,9

76,3

46.5

5)

t13.3

65688

Nm

$30.0

0650891.6

637

$19,5

26,7

49.9

139,3

53,4

99.8

2$

($

19,8

26,7

49.9

1)

Ob

jecti

ve

w4

6.5

8345

rad/s

$40.0

0609874.6

637

$24,3

94,9

86.5

536,8

92,4

79.8

2$

($

12,4

97,4

93.2

7)

p1

21.1

3652

W

$50.0

0568857.6

637

$28,4

42,8

83.1

934,4

31,4

59.8

2$

($

5,9

88,5

76.6

4)

tim

e15.6

1261

min

s

$60.0

0527840.6

637

$31,6

70,4

39.8

231,9

70,4

39.8

2$

($

300,0

00.0

0)

t43.5

28318

Nm

$70.0

0486823.6

637

$34,0

77,6

56.4

629,5

09,4

19.8

2$

$4,5

68,2

36.6

4

$80.0

0445806.6

637

$35,6

64,5

33.1

027,0

48,3

99.8

2$

$8,6

16,1

33.2

7C

on

str

ain

ts

$90.0

0404789.6

637

$36,4

31,0

69.7

424,5

87,3

79.8

2$

$11,8

43,6

89.9

1p1

<=

50

W

$100.0

0363772.6

637

$36,3

77,2

66.3

722,1

26,3

59.8

2$

$14,2

50,9

06.5

5t1

<=

5N

m

$110.0

0322755.6

637

$35,5

03,1

23.0

119,6

65,3

39.8

2$

$15,8

37,7

83.1

9t4

>=

2.5

Nm

$120.0

0281738.6

637

$33,8

08,6

39.6

517,2

04,3

19.8

2$

$16,6

04,3

19.8

2g1

>=

0.0

00

$130.0

0240721.6

637

$31,2

93,8

16.2

914,7

43,2

99.8

2$

$16,5

50,5

16.4

6g2

>=

0

$140.0

0199704.6

637

$27,9

58,6

52.9

212,2

82,2

79.8

2$

$15,6

76,3

73.1

0w

1=

6.2

8ra

d/s

$150.0

0158687.6

637

$23,8

03,1

49.5

69,8

21,2

59.8

2$

$13,9

81,8

89.7

4h

<=

0.7

m

$160.0

0117670.6

637

$18,8

27,3

06.2

07,3

60,2

39.8

2$

$11,4

67,0

66.3

7w

4>

=4.1

8ra

d/s

$170.0

076653.6

6373

$13,0

31,1

22.8

34,8

99,2

19.8

2$

$8,1

31,9

03.0

1r

=0.1

75

m

$180.0

035636.6

6373

$6,4

14,5

99.4

72,4

38,1

99.8

2$

$3,9

76,3

99.6

5g1

<=

1

g2

<=

3

w4

<=

10

rad/s

h>

=0.2

5m

tim

e<

=40

min

s

Pri

ce

Tim

eP

1P

rofi

t

123.0

0$

15.6

1261

21.1

365

16,6

45,2

56.9

8$

$0

.00

$5

,00

0,0

00.0

0

$1

0,0

00

,000

.00

$1

5,0

00

,000

.00

$2

0,0

00

,000

.00

$2

5,0

00

,000

.00

$3

0,0

00

,000

.00

$3

5,0

00

,000

.00

$4

0,0

00

,000

.00

$4

5,0

00

,000

.00

$5

0,0

00

,000

.00

$0

.00

$

50

.00

$

10

0.0

0

$1

50

.00

$

20

0.0

0

Value

Pro

du

ct C

os

t

Re

fin

ed

Mic

roe

co

no

mic

Mo

del

Re

ve

nu

e

Co

sts

Pro

fit

Do

n’t v

ary

these.

QP

R

QC

CC

vf

CR

T dpP

Q

52

Appendix L: CAD Model for Product Design

Side View

Top View

53

Front View

54

Appendix M: NPV/Sensitivity Analysis

55

Appendix N: CBC Survey and Part Worths

Ch

oic

e B

as

ed

Co

njo

int

zeta

om

ega

j=A

j=B

j=C

j=D

Part

Wort

hs (

Beta

s)

Pro

duct

Specs

0$100

11

00

0$100

0.6

0A

BC

NC

0$125

20

11

0$125

0.3

7$100

$125

$150

$150

30

00

1$150

-0.9

8<

33-6

kg

>6

1<

3kg

11

00

0<

3kg

-0.9

515

20

25

13-6

kg

20

10

13-6

kg

0.3

6

>6 k

g3

00

10

>6 k

g0.5

9

215m

in1

01

10

15m

in0.6

3

220m

in2

00

01

20m

in0.0

8F

inal P

art

Wort

hs

25m

in3

10

00

25m

in-0

.71

Price

100

0.6

0

NC

-0.9

4no c

hoic

e u

tility

125

0.3

7

observ

ed c

hoic

es

20

10

10

25

150

-0.9

8

Capacity

2-0

.95

v (s

yste

matic u

tility

)-1

.06035

1.3

6795

1.5

9296

-0.5

3261

-0.9

44

0.3

6

exp(v

)0.3

46335

3.9

27291

4.9

18286

0.5

87070714

0.3

9135

60.5

9

Pj

3%

39%

48%

6%

4%

pedaling t

ime

15

0.6

3

observ

ed

43%

21%

21%

4%

11%

20

0.0

8

25

-0.7

1

LL

-29.3

568

-4.1

3242

-3.1

5521

-2.4

7728922

-7.0

7386

-46.1

9557

observ

ed

20

10

10

25

Pro

duct

Specs

AB

CN

Cprice

$100

$125

$150

$100

$125

$150

0.6

0.3

7-0

.98

<3

3-6

kg

>6

capacity

<3kg

3-6

kg

>6kg

15

20

25

-0.9

50.3

60.5

9

pedaling t

ime

15m

in20m

in25m

in

0.6

30.0

8-0

.71

-3.5

0

-2.5

0

-1.5

0

-0.5

0

0.5

0

1.5

0

2.5

0

3.5

0

4.5

0

05

10

15

20

25

30

Part Worths

ped

alin

g tim

e

-3.5

0

-2.5

0

-1.5

0

-0.5

0

0.5

0

1.5

0

2.5

0

3.5

0

4.5

0

050

100

150

200

Part Worths

Pri

ce

-3.5

0

-2.5

0

-1.5

0

-0.5

0

0.5

0

1.5

0

2.5

0

3.5

0

4.5

0

01

23

45

67

Part Worths

kg

of

clo

thes

Cap

acit

y

Ab

ove w

e h

ave t

aken s

evera

l im

po

rtant ste

ps in b

uild

ing

our M

ark

eting

Mo

del. F

irst,

we h

ave c

reate

d a

set

of

att

rib

ute

s a

nd

levels

(w

e u

se s

urf

ace a

rea and

L/W

ratio

, each w

ith t

hre

e l

evels

). S

eco

nd

, w

e c

reate

d f

our cho

ice o

ptio

ns (in

an a

ctu

al C

BC

yo

u h

ave h

ave s

evera

l sets

of

these c

ho

ice o

ptio

ns a

nd

will b

e a

ble

to

dete

rm

ine t

he p

art

wo

rths w

ith m

ore

data

, b

ut th

is w

ill b

e s

uff

icie

nt fo

r th

is s

imp

le

exam

ple

). N

ext,

we m

ake a

ll n

eccessary

Lo

git m

od

el calc

ula

tio

ns a

nd

then o

ptim

ize o

ur

Part

Wo

rths (

beta

s)

such t

hat

we h

ave th

em

axim

um

lo

g lik

eliho

od

(LL).

F

inally,

we p

lott

ed

the s

pline c

urv

es

asso

cia

ted

with the P

art

Wo

rths f

or each v

ariab

le (

Price,

Surf

ace A

rea,

Ratio

).

We c

an n

ow

use t

hese P

art

Wo

rths in a

pro

duc

t o

ptim

izatio

n.

IMP

OR

TA

NT

:Tho

ug

h I

am

refe

rrin

g t

o the p

rod

uct

att

rib

ute

s h

ere

as S

urf

ace A

rea a

nd

Ratio

(sle

nd

ern

ess

ratio

), w

e m

ust re

ally u

se c

om

mo

n rela

tab

le t

erm

s

when g

ivin

g s

urv

eys to

users

. T

hus S

urf

ace A

rea

sho

uld

be term

ed

"S

helf

Sp

ace"

and

Ratio

sho

uld

be

term

ed

"S

kin

nin

ess".

56

Appendix O: Conjoint Analysis-Maximum Demand

obj. funct.

constraints

Attribute Information from Conjoint Survey Our Final Product

Pedaling time Specification Part Worth Spline Functions

Level 15 20 25 Pedaling time 15.0 0.63164

Est. Beta 0.63 0.08 -0.71 Capacity 5.4 0.635466

Price 107 0.652536

Capacity 0.0

Level 2 4 6 "v" % of Market that Chooses Our Product

Est. Beta -0.95 0.36 0.59 Our Product 1.92 95%

No Choice -0.94 5%

Price

Level 100.00$ 125.00$ 150.00$

Est. Beta 0.60 0.37 -0.98 Market Size

Total Consumers 560,000

Qm 529604

Manufacturing Costs

Base Cost 300,000.00$ Profitability = Revenue - Costs

Unit Cost per Total Cost Revenue 56,839,406$

Volume 60.00$ per 6kg machine 54.13$ Costs 28,965,932$

(and behind these numbers is the engineering model) Profit 27,873,474$

Constraints

Min Max

Pedaling Time 15 25

Capacity 2 6

Price 100.00$ 150.00$

Engineering ModelVariables

g1 0.602192

g2 2.013265

h 0.548122 m

w4 4.18 rad/s

Constants

r 0.175 m

w1 6.28 rad/s

Equations

t1 7.379224 Nm

Objective w4 6.852322 rad/s

p1 46.34153 W

time 15 mins

t4 8.051722 Nm

capacity 52.73548 lit

capacity 5.412715 kg of clothes

Constraints

p1 <= 50 W

t1 <= 5 Nm

t4 = 2.5 Nm

g1 >= 0.000

g2 >= 0

w1 = 6.28 rad/s

h <= 0.7 m

w4 >= 4.18 rad/s

r = 0.175 m

g1 <= 1

g2 <= 3

w4 <= 10 rad/s

h >= 0.25 m

time <= 40 mins

From the Marketing (CBC) tab we get our Part Worth Functions (top right box), and examining that funciton we can obtain the optimal values for a variety of purposes.

Here we are maximizing the demand, shown in the Market Size box above. Notice that when we maximize demand subject to the constraints of the market

we have actually made a poor business decision, because we wind up running the business into a defecit.

Furthermore, we have exceeded the engineering constraints (Stress in Engineering Model) of the design. Thus the product will be likely to break, causing us to probably get sued over the poor design (even more expensive).

57

Appendix P: Conjoint Analysis-Maximum Profit (w/o Engg. Constraint)

Linked Model (Maximize Profit without Engineering Constraints) parameter

(yours will be much much more complicated) variable

note: the Part Worth values come from the worksheet "3-levelCBCExample" function

obj. funct.

constraints


Ratio Specification Part Worth Spline Functions

Level 15 20 25 Pedaling time 15.0 0.63164

Est. Beta 0.63 0.08 -0.71 Capacity 3.4 0.103332

Price 137 -0.15794

Surface Area



No Choice -0.94 18%

Price

Level 100.00$ 125.00$ 150.00$



Qm 459104

Manufacturing Costs



Volume 60.00$ per 6kg machine34.37$ Costs 16,078,483$


Constraints

Min Max

Ratio 15 25

Surf Area 2 6

Price 100.00$ 150.00$


g1 0.783224

g2 1.547923

h 0.220981 m

w4 13.22537 rad/s

Constants

r 0.175 m

w1 6.28 rad/s

Equations

t1 2.975007 Nm


p1 18.68304 W

time 15 mins

t4 3.246131 Nm



Constraints

p1 <= 50 W

t1 <= 5 Nm

t4 = 2.5 Nm

g1 >= 0.000

g2 >= 0

w1 = 6.28 rad/s

h <= 0.7 m

w4 >= 4.18 rad/s

r = 0.175 m

g1 <= 1

g2 <= 3

w4 <= 10 rad/s

h >= 0.25 m

time <= 40 mins


Here we are maximizing the prof it, shown in the Profitability box above. Notice that when we maximize prof it shown here we are not incorporating the

engineering realities of the product. Unfortunatley, while we maximize our prof it with this proposed design we neglect the

Furthermore, we have exceeded the engineering constraints of the design (Stress in Engineering Model to the lef t). Thus the product will be likely to break, causing us to probably get sued over the poor design (even more

expensive).

58

Appendix Q: Conjoint Analysis-Maximum Profit (with Engg. Constraint) Linked Model (Maximize Profit with Engineering Constraints) parameter

(yours will be much much more complicated) variable

note: the Part Worth values come from the worksheet "3-levelCBCExample" function

obj. funct.

constraints


Ratio Specification Part Worth Spline Functions

Level 15 20 25 Ratio 15.0 0.63164

Est. Beta 0.63 0.08 -0.71 Surf Area 3.7 0.21461

Price 139 -0.22888

Surface Area



No Choice -0.94 17%

Price

Level 100.00$ 125.00$ 150.00$



Qm 462398

Manufacturing Costs



Volume 60.00$ cubic inch 36.55$ Costs 17,202,955$


Constraints

Min Max

Ratio 15 25

Surf Area 2 6

Price 100.00$ 150.00$


g1 0.529084

g2 2.291455

h 0.25 m

0

Constants

r 0.175 m

w1 6.28 rad/s

Equations

t1 3.365688 Nm


p1 21.13652 W

time 15 mins

t4 3.672416 Nm



Constraints

p1 <= 50 W

t1 <= 5 Nm

t4 = 2.5 Nm

g1 >= 0.000

g2 >= 0

w1 = 6.28 rad/s

h <= 0.7 m

w4 >= 4.18 rad/s

r = 0.175 m

g1 <= 1

g2 <= 3

w4 <= 10 rad/s

h >= 0.25 m

time <= 40 mins


Here we are maximizing the prof it, shown in the Profitability box above. Notice that when we maximize prof it shown here we are not incorporating the

engineering realities of the product. Unfortunatley, while we maximize our prof it with this proposed design we neglect the

Furthermore, we have exceeded the engineering constraints of the design (Stress in Engineering Model to the lef t). Thus the product will be likely to break, causing us to probably get sued over the poor design (even more

expensive).

59

Appendix Q: Linked Model

Linked Model (Maximize Profit with Engineering Constraints)(yours will be much much more complicated)

note: the Part Worth values come from the worksheet "3-levelCBCExample"

Attribute Information from Conjoint Survey Our Final Product Finite Differencing

Ratio Specification Part Worth Spline Functions Specification Part Worth Spline Functions

Level 15 20 25 Pedaling time 15.0 0.63164 15.75000025 0.56466149

Est. Beta 0.63 0.08 -0.71 Capacity 5.4 0.635466 5.68337971 0.62548214

Price 107 0.652536 112.6940304 0.62670546

Surface Area



No Choice -0.94 5%

Price

Level 100.00$ 125.00$ 150.00$ Linearized Elasticities

Est. Beta 0.60 0.37 -0.98 Market Size Var "v" % of Market Qm dQm/dVar

Total Consumers 560,000 Pedaling time 1.85 94% 527619.6 -2645.1817

Qm 529604 Capacity 1.91 95% 529315.3 -1065.181

Price 1.89 94% 528852.4 -139.9748


g1 0.5709847

g2 2.1232988

h 0.5481271 m

w4 4.1800001 rad/s

Constants

r 0.175 m

w1 6.28 rad/s

Constraints

Min Max Equations

Ratio 15 25 t1 7.3792982 Nm

Surf Area 2 6 Objective w4 6.8523217 rad/s

Price $100 150.00$ p1 46.341993 W

time 15 mins

t4 8.0518034 Nm



Constraints

p1 <= 50 W

t1 <= 5 Nm

t4 = 2.5 Nm

g1 >= 0.000

g2 >= 0

w1 = 6.28 rad/s

h <= 0.7 m

w4 >= 4.18 rad/s

r = 0.175 m

g1 <= 1

g2 <= 3

w4 <= 10 rad/s

h >= 0.25 m

time <= 40 mins

Here we have determined the f inite dif ferences associated with a small movement f rom the "base design" as used in in the Refined MicroEconomic Model. This allows us to calculate the associated linear elasticities in a much more accurate

way than previously. The elasticities (shown at right beneath the arrow) can then be used in a New MicroEconomic Formulation.

T

dpPQ

60

Appendix R: Life Cycle Analysis on SimaPro 7.3

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Eco Indicator 99 (H) Nirmal Lifecycle Damage Assessment

Eco Indicator 99 (H) Nirmal Lifecycle as Single Score

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Appendix S: Existing Patents

निर्मल (nirmal) - university of michigandesci501/2012/apd-2012-04.pdfmachines but the...

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