Flashlight Assembly

By: Group 5

Agacita, AngelicaPanes, Isabel FruileneMabasa, LanmarkAndales, Ian

Theoretical Background• There are three special interpretations that must be

considered in the left-hand/right-hand chart as stated by Aft

(2000). First is that the hands do not perform inspection.

Second is that transportations are defined as movements

of the hands from one location to another location.

Lastly, holds are considered to be delays.

• There are factors or classification as well, to be considered in

the process of improving the productivity of the worker.

These are the use of the human body, workplace

arrangement and the design of tools and equipment.

• An ideal worker in the workstation must be productive as to

keeping a sufficient amount of work. There must not be an

idle time at all and everything has to be balance, the starting

and stopping times of the hands (based from Principle 2 of

motion economy principles).

• Rhythm must be followed where there is a moderate flow of

the worker’s performance because a slowing pace and

speeding up makes the operator less productive (Principle 4).

• According to O’Neill (2007), a machine is purely viewed as

an overhead cost to the organization, not as a potential tool

for strategic advantage.

•As the company reorganize, whether enlarging or

reducing their work forces, the cost associated with

housing employees and providing their work tools

continues to increase.

•A research study made by Karasek and Theorell (1990)

proved that an enhanced control over the workspace

and job control decreases or reduced the risk of stress

on the workers. They also argue that that there are two

significant sources of stress in the work environment;

the way jobs are designed and the design of work

environments.

• In order to keep things systematized, these principles of

ergonomics must be taken into consideration:

• Principle 1- Work in neutral postures,

• Principle 2 – Keep everything in easy reach, Principle 4 –

Work at proper heights,

• Principle 5 – Reduce excessive motions,

• Principle 9 – Move, exercise and stretch

• Principle 10–Maintain a comfortable environment

• In designing a work station, it is important to know the

relevance and taking into considerations the variations of body

measurements, whether you are designing for the average or the extreme.

•ISO defines usability as “The extent to which a

product can be used by specified users to

achieve specified goals with effectiveness,

efficiency and satisfaction in a specified context

of use.”

•dexterity or fine motor skills are the

coordination of the small muscle movements

which occurs in the fingers, usually in

coordination of the eyes.

Methodology

The proponents made some observations in the process

of the flashlight assembly. The data gathered were being

analyzed and the weaknesses were being determined.

Books were used as the secondary source for

constructing a left-hand/right-hand chart. Only one person

is being considered as the performer of the activity. The

chart was constructed as to the details of every operation.

In which, the weaknesses gathered were the bases for

generating proposals for improvement.

Statement of the problem• The purpose of this activity is to assess the present method in

the flashlight assembly considering the 3 factors in improving

the worker’s productivity where it also answers the following

questions:

▫What are the unnecessary operations to be eliminated?

▫What are the sequences of activities that need to be changed

or simplified?

• Based on the findings of the study, what proposals could be

recommended improving the existing method of flashlight

assembly.

Objectives:• Investigate specific operations in order to

improve them by using operations chart

•Eliminate all unnecessary motions and to arrange the remaining motions in the best sequence

Apparatus: Flashlight

PRESENT METHOD

WORK STATION DESIGN

FINISHED ASSEMBLIES

CASES

BULBS

REFLECTORS

LENSES BOTTOMS

CASES TOPS

WORKER

WEAKNESSES:

•Principle 1 – “The two hands should begin as

well as complete their motions at the same time”

The present method failed to adapt the first

principle because the right hand did most of the

operations. It is seen that the there was a

transportation made from the right hand to the left

hand, in which it is unnecessary. In result, the left

hand made most of the idleness instead of having a

fair routine in the operations.

 

•Principle 2 – “Motions of the arms should

be made in opposite and symmetrical

directions, and should be made

simultaneously”

The present method failed to perform in

this manner since the left hand is in idle and

does not permit the operator to work faster.

There must be the same command for both of

the hands in order to make the operations

effective.

•Principle 8 – “Work should be arranged to

permit easy and natural rhythm wherever

possible”

Although, the operation permits the right-

handed person to do the task, the location of the

materials are not appropriate for the right hand to

develop the certain habit. The rhythm of the

process forces the operator to take the habits

instead of allowing both hands to perform normally.

•Principle 9 – “Eye fixations should be as

few and as close together as possible”

The distances or the arrangements of

the materials make the method ineffective

in such a way that the operator tends to

search for the next material. The operator

has the tendency to get disorganize and

interrupts the normal motion cycle.

PROPOSED METHOD

WORK STATION DESIGN

WORKER

CASES

BULBS TOP

RINGS

REAR

CAPS

LENSES REFLECTORS

FINISHED ASSEMBLIES

DISTANCES FROM THE WORKER:

FINISHED ASSEMBLIES -13 inches

CASES -6 inches

TEST JIG -4 inches

MAGNETIC HOLDER -4 inches

REFLECTORS -6 inches

LENSES -8 inches

BULBS -10 inches

TOP RINGS -8 inches

REAR CAPS -10 inches

LEGEND:

-TEST JIG

-MAGNETIC HOLDER

HEIGHT OF THE TABLE: 3.01 ft

VERTICAL CLEARANCE: 2.10 ft

HEIGHT OF THE CHAIR: 2.04 FT

4 ft

3 ft

Magnetic holder - flashlight

STEPS IN MAKING A TEST JIG

SCHEMATIC OF THE TEST JIG

1. Remove the HS-flat of the flashlight 2. Connect the wire, black for negative and red for the positive to the HS-flat, then

solder. 3. Connect the other ends of the wire, black for positive and red for the negative of

the dry cell. 4. Enclose the test jig with any recyclable case.

HS -FLAT

DRY CELL

+ -

- +

WORKSTATION DESIGN

2.10 FT

3.01 FT

2.04 FT

Summary of the Left-Right Hand Chart

PRESENT LEFT-RIGHT HAND CHART

Left Hand Right Hand

Transportation Operation Transportation Operation

1 3 17 21

PROPOSED LEFT-RIGHT HAND CHART

Left HandRight Hand

Transportation Operation Transportation Operation

7 8 8 9

COST-BENEFIT ANALYSISTOOLS QTY COST (Php) BENEFIT

*MAGNETIC HOLDER 1 849.25 The operator will no longer hold the

case of the flashlight

TESTJIG HS-flat of the flashlight Electrical wire (3’ – black

and red) Dry cell (1.5V) Soldering wire Soldering iron

11

111

20 5

34 3 49

The dry cells will no longer be part of the operations, instead it make use of the testing of the bulb before the latter will be attached to the reflector.

1/2 x 4 x 8Plywood – ordinary (P170/pc)

2 340Will be used to construct a table and chair in which it adds comfort and the operator will have a chance to take a rest after long hours of standing.

2 x 2 x 10 – mahogany (P93/pc)

4 372

COST-BENEFIT ANALYSISTOOLS QTY COST (Php) BENEFIT

Common nails – 2” ( 35 / kg)

1 kg. 35Will be used for constructing a table and chair

Labor for 1 day (305/day)

3 915

TOTAL 2622.25

* Total cost is subject to change due to shipping cost of magnetic holder, since it is made available in www.aircraftspruce.com

STRENGTH:

•Principles 1 – 3: “Two hands begin and complete

their motions at the same time..Two hands should

not be idle at the same time..and Motions are

made in opposite and symmetrical directions”

The proposed method used of the two hands in

which the motions made fair distribution of the

operation. Although, there was an idle on the part of

the left hand (in holding the lens) but the thought of

having both hands work simultaneously has been one

of the advantages.

• Principle 8 – 9: “Work should be arranged to permit

easy and natural rhythm..Eye fixations should be as

few and as close together as possible”

The arrangement of the spare parts or materials for

flashlight assembly is made closer in order to work easily

and to avoid stress on the part of the operator. The

distances are as well made easy to reach and arranged

according to the sequence of the operation. On the part of

the operator, he or she is not force to follow habits for the

sake of symmetry since most of the operations are done

on the right hand, to compensate the right handed person.

•Principle 16–17:“The height of the work place

and the chair should be arranged..A chair of the

type and height to permit good posture should

be provided”

Bad posture can tire the operator much more

quickly than good posture. In which, tired operator is

not as productive as rested workers. Good posture

is encouraged through the use of comfortable chairs

allowing the operator to sit or stand.

• Principle 18-19:“The hands should be relieved of all work

that can be done by a jig or fixture..Two or more tools

should be combined wherever possible”

The added tools or fixtures eliminate the need for the

hands to function as holding the materials and promote the

performance of simultaneous motions. It is very important to

respect the capabilities of the human since he or she is not

automated. Providing the workstation with devices that will help

the operator, although it is costly, much make sense to what

productivity is concern. As stated by Aft (2000), use people

where they are most effective and use machines where they are

most effective.

CONCLUSIONUnnecessary movements cause delay and delay means additional cost.

So, in this, unnecessary movements should be removed and that includes

the transferring of the material form one hand to the other and doing the

job one at a time where in fact the operator can do multiple jobs on the

same time. Distance traveled by the worker or the material really matters,

the closer the distance of the materials from the worker is, the better it

would be and the process should be systematic in such a way that the

materials should be orderly sequenced by their use. The goal of this work

is to obtain the best method to perform the operation and these include the

performing of two jobs at a time and letting both hands work beneficially

with each other to minimize the time consumed in performing a job.

RECOMMENDATIONTo obtain the improvement goals, the researchers

recommend the company to apply the proposed method

which is the best possible method in improving the

productivity of the worker. The proposed method includes the

arrangement of the work station putting the first material to be

used on the nearest place from the worker followed by the

next material and so on. Also on the proposed method

suggests eliminating the unnecessary movements which

cause delay. Management in imposing the proposed method

is advised and training the worker to be skilled on the

proposed method is urged.