09 أيلول، 15 09 أيلول، 15 09 أيلول، 1509 أيلول، 15 09 أيلول، 15 09...

/ /١٤٤٤ ٠٩ ٢٩ 13:10Dr.Kasser Naser Mansour- KAU-KSA1

/ /١٤٤٤ ٠٩ ٢٩ 13:106 Dr.Kasser Naser Mansour- KAU-KSA

أن يجب المناسب الترتيب قرار نتخذ أن قبلالتالية األسئلة عن :نجيب

1. What centers should the layout include?2. How much space and capacity does each center

need?3. How should each center’s space be configured?4. Where should each center be located?

Layout Planning Questions تخطيط مسائلالترتيب

Location Dimensions ابعادالموقع

• The location of a center has two dimensions:

1. Relative location: The placement of a center relative to other centers.

2. Absolute location: The particular space that the center occupies within the facility.

How Process Layout العملية ترتيب يتم كيف fits the Operations Management Philosophy

Operations As a Competitive Weapon

Operations StrategyProject Management Process Strategy

Process AnalysisProcess Performance and Quality

Constraint ManagementProcess Layout

Lean Systems

Supply Chain StrategyLocation

Inventory ManagementForecasting

Sales and Operations PlanningResource Planning

Scheduling

Product LayoutInput Data and Activities

1 .Flow of Materials 2 .Activity Relationships

3 .Relationship Diagram

4 .Space Requirements 5 .Space Available

6 .Space Relationship Diagram

7 .Modifying Considerations 8 .Practical Limitations

9 .Develop Layout Alternatives

10 .Evaluation

An

alys

isS

earc

hS

elec

tio

n

Absolute Locations vs. Relative Locations

Original layout

Frozen foods

Dry groceries

Bread Vegetables

Meats

Frozen foods

Dry groceries

BreadVegetables

Meats

Revised layout

Four of the absolute locations have changed but

not the relative locations .

Strategic Issues

• Layout choices can help communicate an organization’s product plans and competitive priorities.

• Altering a layout can affect an organization and how well it meets its competitive priorities in the following ways:

1. Increasing customer satisfaction and sales at a retail store.2. Facilitating the flow of materials and information.3. Increasing the efficient utilization of labor and equipment.4. Reducing hazards to workers.5. Improving employee morale.6. Improving communication.

Performance Criteria

• Customer satisfaction• Level of capital investment• Requirements for materials handling• Ease of stock picking• Work environment and “atmosphere”• Ease of equipment maintenance• Employee and internal customer attitudes• Amount of flexibility needed• Customer convenience and levels of sales

Types of Layouts

• Flexible-flow layout: A layout that organizes resources (employees) and equipment by function rather than by service or product.

• Line-flow layout: A layout in which workstations or departments are arranged in a linear path.

• Hybrid layout: An arrangement in which some portions of the facility have a flexible-flow and others have a line-flow layout.

• Fixed-position layout: An arrangement in which service or manufacturing site is fixed in place; employees along with their equipment, come to the site to do their work.

A Flexible Flow Layout

FoundryMilling

machines

LathesGrinding

Painting Drills

Office

Welding

Forging

A job shop has a flexible-flow layout.

• ( النقل تكاليف مسألة هي هنا المسألة: هي( حلها وطرائق ، والمناولة

البسيطة- 1 المخططات طريقةالعملية- 2 تتابع تحليل طريقةالمقطوعة- 3 المسافة في العبء تحليل طريقةالحاسب- 4 بستخدام التحليل طريقة

/ /١٤٤٤ ٠٩ ٢٩ 13:1016 Dr.Kasser Naser Mansour- KAU-KSA

18

XA

O

E

AAbsolutely NecessaryEEspecially ImportantIImportant

OOrdinary Closeness O.K.UUnimportantXUndesirable

A and X > E > I > O > U

20

Layout Design الترتيب تصميم• Three concepts: مفاهيم :ثالثة

– Layout Evaluation الترتيب تقييم– Layout Construction الترتيب تشكيل– Layout Improvement الترتيب أهمية

• What to use as input data? كمدخالت؟ بيانات نستخدم ماذا – Relationships – closeness ratings وأماكن والشعب األقسام بين المغلقة العالقات عدد

العمل• Subjective• May take long time to prepare

– Flow data البيانات تدفق• Objective• May not be very stable

• How to Evaluate the Layout Plans? – Objective Function الترتيب خطط نقيم كيف– Distance Based– Adjacency Based

21

Layout Evaluation تقييم التريتب

An Algorithm جيدة خطط بين تقارن التقيم عمليةسيء قائم وآخر

s = g (X ) يلي كما نموذج :نطوnر–Adjacency-based scoring (Komsuluk Bazli Skorlama)

• Based on the relationship chart and diagram

• Xi is the number of times an adjacency i is satisfied, i=A, E, I, O, U, X• Aldep uses (wi values) A=64, E=16, I=4, O=1, U=0, and X=-1024• Scoring model has intuitive appeal; the ranking of layouts is sensitive to the

weight values. Layout “B” may be preferred to “C” with certain weights but not with others.

• Therefore, the specification of the weights is very important.• The weights wi can also be represented by the flow amounts between the

adjacent departments instead of scores assigned to A, E, I, O, U, X.

6

1

i

iiXwsMax

22

12

34

56

7

12

34

56

7

UU

UU

IE

UI

OU

A

OI

UI

IE

U

OU

EReceivingReceiving

MillingMilling

PressPress

Screw MachineScrew Machine

AssemblyAssembly

PlatingPlating

ShippingShipping

3

Press

7

Shipping

6Plating

2

Milling

4

Screw Machine

5

Assembly

1

Receiving

A

E I

E

O

I

O

1234567

1 2 3 4 5 6 7

I OE I U

O U

AE

4+1 =5

16+4+0 =20

1+0 =1

----

64 =64

16 =16

Total Score 106

Example

U U

23

Exercise:Exercise: Find the score of the layout shown below. Use A=8, E=4, I=2, O=1, U=0 and X=-8.

12

34

56

7

12

34

56

7

UU

UU

IE

UI

OU

A

OI

UI

IE

U

OU

EReceivingReceiving

MillingMilling

PressPress

Screw MachineScrew Machine

AssemblyAssembly

PlatingPlating

ShippingShipping

3Press

7Shipping

6Plating

4Screw

Machine

1Receiving

2Milling

5Assembly

24

Layout Evaluation (cont’d)–Distance-based scoring (Mesafe Bazli Skorlama)

• Approximate the cost of flow between activities• Requires explicit evaluation of the flow volumes and costs

• cij covers both the i to j and the j to i material flows

• Dij can be determined with any appropriate distance metric–Often the rectilinear distance between department centroids

• Assumes that the material flow system has already been specified (cij=flow required* cost /flow-distance)

• Assumes that the variable flow cost is proportional to distance• Distance often depends on the aisle layout and material handling

equipment

1

1 1

m

i

m

ijijijDcsMin

25

Layout Evaluation – Distance Based Scoring

Example

A B

C D

Initial Layout

From/To A B C DA - 2 4 4B 1 - 1 3C 2 1 - 2D 4 1 0 -

Flow Data

From/To A B C DA - 40 25 55B 40 - 65 25C 25 65 - 40D 55 25 40 -

Distance DataFrom/To A B C D Total

A - 80 100 220 400B 40 - 65 75 180C 50 65 - 80 195D 220 25 0 - 245

Total 310 170 165 375 1020

Total Cost

26

Layout Evaluation – Distance-Based Scoring

–Distance-based scoring–Impact of aisle layout and direction of travel

A B

C D

Warehouse LayoutsOut-and-back Pattern

• The most basic warehouse layout is the out-and-back pattern. The numbers indicate storage areas for same or similar items.

Dock Aisle

Storage area

Storage area

3556427

1554427

Warehouse Layouts Zone System

Click to add titleZones Zones Control

station Shipping doors

Tractor trailer

Tractor trailer

Overflow

Feeder lines

Feeder lines

Office Layouts المكتب تخطيط

• Most formal procedures for designing office layouts try to maximize the proximity of workers whose jobs require frequent interaction.

• Privacy is another key factor in office design.• Four common office layouts:

1. Traditional layouts

2. Office landscaping (cubicles/movable partitions)

3. Activity settings

4. Electronic cottages (Telecommuting)

Line Flow Layout

Station 1 Station 2 Station 3 Station 4

A production line has a line-flow layout.

Group Technology (GT)

• Group Technology (GT) is an option for achieving line-flow layouts with low-volume processes; this technique creates cells not limited to just one worker and has a unique way of selecting work to be done by the cell.

• The GT method groups parts or products with similar characteristics into families and sets aside groups of machines for their production.

Before Group Technology

Drilling

D D

D D

Grinding

G G

G G

G G

Milling

M M

M M

M M

Assembly

A A

A A

Lathing

Receiving and shipping

L

L L

L L

L L

L

Jumbled flows in a job shop without GT cellsJumbled flows in a job shop without GT cells

Applied Group TechnologyLine flows in a job shop with three GT cellsLine flows in a job shop with three GT cells

Cell 3

L M G G

Cell 1 Cell 2

Assembly area

A A

L M DL

L MShipping

D

Receiving

G

Designing Flexible-Flow Layouts

• Step 1: Gather information– Space requirements by center– Available space– Closeness factors: which centers need to be located close to one

another.

• Closeness matrix: A table that gives a measure of the relative importance of each pair of centers being located close together.

• Step 2: Develop a Block plan: A plan that allocates space and indicates placement of each department.

• Step 3: Design a detailed layout.

Gather Information

100'

150'

3 6 4

1 2 5

Current Block Plan

Department Area Needed (ft2)

1 .Administration3,5002 .Social services2,6003 .Institutions2,4004 .Accounting1,6005 .Education1,5006 .Internal audit3,400

Total15,000

Space Requirements

Example : Office of Budget Management

100'

150'

3 6 4

1 2 5 Closeness Matrix

Trips between Departments

Department 1 2 3 4 5 6

1. Administration —

2. Social services —

3. Institutions —

4. Accounting —

5. Education —

6. Internal audit —

3 6 5 6 10

8 1 1

3 9

2

1

Departments 1 and 6 have the most interaction.Departments 3 and 5 have the next highest.

Departments 2 and 3 have next priority.

Example 8.1 Office of Budget Management

100'

150'

100'

150'

3 6 4

1 2 5 Proposed Block Plan

First put departments 1 and 6 close together

1

6

Next put departments 3 and 5 close together

5

3

Then put departments 2 and 3 close together

2

4

• Weighted-distance method: A mathematical model used to evaluate flexible-flow layouts based on proximity factors.

• Euclidean distance is the straight-line distance, or shortest possible path, between two points.

• Rectilinear distance: The distance between two points with a series of 90 degree turns, as along city blocks.

Applying the Weighted- Distance Method

Distance Measures

Rectilinear DistanceRectilinear Distance

ddABAB = |= |xxAA –– x xBB| + || + |yyAA – – yyBB||

Euclidian DistanceEuclidian Distance

ddABAB = (= (xxAA –– x xBB))22 + ( + (yyAA – – yyBB))22

©2007 Pearson Education

Example 2 : Load Distance Analysis

Current Plan Proposed Plan

Dept Closeness Distance DistancePair Factor, w d wd Score d wd Score

1,2 3 1 3 2 61,3 6 1 6 3 181,4 5 3 15 1 51,5 6 2 12 2 121,6 10 2 20 1 102,3 8 2 16 1 82,4 1 2 2 1 12,5 1 1 1 2 23,4 3 2 6 2 63,5 9 3 27 1 94,5 2 1 2 1 25,6 1 2 2 3 3

ld =112 ld = 82

Calculating the WD Score

Designing Line-Flow Layouts

• Line balancing is the assignment of work to stations in a line so as to achieve the desired output rate with the smallest number of workstations.– Work elements are the smallest units of work that can be performed

independently.– Immediate predecessors are work elements that must be done before

the next element can begin.– Precedence diagram allows one to visualize immediate predecessors

better; work elements are denoted by circles, with the time required to perform the work shown below each circle.

Line Balancing Example 8.3Example 8.3

Green Grass, Inc., a manufacturer of lawn & garden equipment, is designing an assembly line to produce a new fertilizer spreader, the Big Broadcaster. Using the following information, construct a precedence diagram for the Big Broadcaster.


Line Balancing Green Grass, IncGreen Grass, Inc..

66

E2020

H

1818

I

4040

D

3030

B

2525

F

5050

C4040

A

1515

G

AA Bolt leg frame to hopperBolt leg frame to hopper 4040 NoneNoneBB Insert impeller shaftInsert impeller shaft 30 30 AACC Attach axleAttach axle 5050 AADD Attach agitatorAttach agitator 4040 BBEE Attach drive wheelAttach drive wheel 66 BBFF Attach free wheelAttach free wheel 2525 CCGG Mount lower postMount lower post 1515 CCHH Attach controlsAttach controls 2020 D, ED, EII Mount nameplateMount nameplate 1818 F, GF, G

TotalTotal 244244

WorkWork Time Time Immediate ImmediateElementElement DescriptionDescription (sec) (sec) Predecessor(s) Predecessor(s)

Desired Output and Cycle Time

• Desired output rate, r must be matched to the staffing or production plan.

Cycle time, c is the maximum time allowed for work on a unit at each station:

1

rc=

Designing Line-Flow Layouts

• Line balancing is the assignment of work to stations in a line so as to achieve the desired output rate with the smallest number of workstations.– Work elements are the smallest units of work that can be performed

independently.– Immediate predecessors are work elements that must be done before

the next element can begin.– Precedence diagram allows one to visualize immediate predecessors

better; work elements are denoted by circles, with the time required to perform the work shown below each circle.

Line Balancing Example 8.3Example 8.3

Green Grass, Inc., a manufacturer of lawn & garden equipment, is designing an assembly line to produce a new fertilizer spreader, the Big Broadcaster. Using the following information, construct a precedence diagram for the Big Broadcaster.


Line Balancing Green Grass, IncGreen Grass, Inc..

66

E2020

H

1818

I

4040

D

3030

B

2525

F

5050

C4040

A

1515

G

AA Bolt leg frame to hopperBolt leg frame to hopper 4040 NoneNoneBB Insert impeller shaftInsert impeller shaft 30 30 AACC Attach axleAttach axle 5050 AADD Attach agitatorAttach agitator 4040 BBEE Attach drive wheelAttach drive wheel 66 BBFF Attach free wheelAttach free wheel 2525 CCGG Mount lower postMount lower post 1515 CCHH Attach controlsAttach controls 2020 D, ED, EII Mount nameplateMount nameplate 1818 F, GF, G

TotalTotal 244244

WorkWork Time Time Immediate ImmediateElementElement DescriptionDescription (sec) (sec) Predecessor(s) Predecessor(s)

Theoretical Minimum

Theoretical minimum (TM ) is a benchmark or goal for the smallest number of stations possible, where total time required to assemble each unit (the sum of all work-element standard times) is divided by the cycle time. It must be rounded up

Idle time is the total unproductive time for all stations in the assembly of each unit.

Efficiency (%) is the ratio of productive time to total time.

Balance Delay is the amount by which efficiency falls short of 100%.

Output Rate and Cycle TimeExample.4

Green Grass, Inc. • Desired output rate, r = 2400/week Plant operates 40 hours/week r = 2400/40 = 60 units/hour

Cycle time, c = 1/60

= 1 minute/unit

= 60 seconds/unit

1

r

Calculations for Example.4 continued

Theoretical minimum (TM ) - sum of all work-element standard times divided by the cycle time.

TM = 244 seconds/60 seconds = 4.067 It must be rounded up to 5 stations

Cycle time: c = 1/60 = 1 minute/unit = 60 seconds/unit

Efficiency (%) - ratio of productive time to total time.

Efficiency = [244/5(60)]100 = 81.3%

Balance Delay - amount by which efficiency falls short of 100%.

(100 − 81.3) = 18.7%

Line Balancing Big BroadcasterBig Broadcaster

cc = 60 seconds/unit = 60 seconds/unitTM = 5 stationsTM = 5 stationsEfficiency = 81.3%Efficiency = 81.3%

S1

S2S3

40

66

2020

50

1515

1818

E30

25

4040H

I

D

B

FC

A

G

S1 A A 40 20

S2 B,C C 50 10

S3 B,F,G B 30 30E,F,G F 55 5

Cumm IdleStation Candidate Choice Time Time


S1

S2S3

S5S4 66

E2020

H

1818

I

4040

D

3030

B

2525

F

5050

C4040

A

1515

G

Green Grass, Inc. Green Grass, Inc. Line Balancing SolutionLine Balancing Solution

cc = 60 seconds/unit = 60 seconds/unitTM = 5 stationsTM = 5 stationsEfficiency = 81.3%Efficiency = 81.3%

The goal is to cluster the work elements into 5 workstations so that the number of work-stations is minimized, and the cycle time of 60 seconds is not violated. Here we use the trial-and-error method to find a solution, although commercial software packages are also available.

Other Considerations

In addition to balancing a line, managers must also consider four other options:

1. Pacing: The movement of product from one station to the next as soon as the cycle time has elapsed.

2. Behavioral factors of workers.3. Number of models produced: A mixed-model line

produces several items belonging to the same family.

4. Cycle times depend on the desired output rate, and efficiency varies considerably with the cycle time selected.

NL8. En produkt består av 9 st detaljer (D1-D9) vilka monteras ihop enligt strukturennedan:

A

D7

E

D4B

C G

D5

DD8

D1

D2

D3

D6

D9

F

Tiderna för att utföra monteringsoperationerna

är enl. följande:

M1, Delmontering D1, D2 och D3: 12 min

M2, Delmontering D4 och D5: 20 min

M3, Delmontering A och B: 10 min



M6, Delmontering C och D: 22 min

M7, Slutmontering E och F: 16 min

a) Åskådliggör de olika stegen i monteringen

enligt strukturen i ett precedensdiagram

(nätverk). Kalla monteringsaktiviteterna M1,

M2, ..., M7.

b) Minimera antalet monteringsstationer om

cykeltiden tillåts vara högst 28 min. Använd

"längsta operationstid först"

c) Bestäm balanseringsförlusten.

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