05 - layout strategy

Layout Strategy

Dr. Keong LeongManagement Department

UNLV

When you complete this class you should be able to: Explain the strategic importance of

layout decisions Develop a good layout for a process-

oriented facility Balance production flow in a

repetitive or product-oriented facility using the assembly line balancing technique

Key Learning Outcome

Outline

Global Company Profile: McDonalds The Strategic Importance of Layout

Decisions Process-Oriented and Repetitive Layout Assembly Line Balancing

(Principles of Operations Management, Heizer & Render, 7th Edition)

McDonalds New Layout

Redesigning all 30,000 outlets around the world Three separate dining areas

Linger zone with comfortable chairs and Wi-Ficonnections

Grab and go zone with tall counters Flexible zone for kids and families

Facility layout is a source of competitive advantage


McDonalds

Savings of $100,000,000 per year in food costs

New Kitchen Layout


Facility Layout Strategy

The objective of layout strategy is to develop a cost-effective layout that will meet a firms competitive needs

Location or arrangement of everything within & around a facility to achieve: Higher utilization of space, equipment, and people Improved flow of information, materials, or people Improved employee morale and safer working

conditions Improved customer/client interaction Flexibility


Surgery

Radiology

ER Triage Room

ER Beds Pharmacy

Emergency room admissions

Billing/exit

Laboratories

Patient A - broken leg

Patient B - erratic heart pacemaker

Figure 9.3Figure 9.3

Process-Oriented Layout


Minimize cost = Xij Cijn

i = 1

n

j = 1

where n = total number of work centers or departments

i, j = individual departmentsXij = number of loads moved from

department i to department jCij = cost to move a load between

department i and department j

Process-Oriented Layout


Process Layout Example

Arrange six departments in a factory to minimize the material handling costs. Each department is 20 x 20 feet and the building is 60 feet long and 40 feet wide. Construct a from-to matrix Determine the space requirements Develop an initial schematic diagram Determine the cost of this layout Try to improve the layout Prepare a detailed plan


DepartmentDepartment AssemblyAssembly PaintingPainting MachineMachine ReceivingReceiving ShippingShipping TestingTesting(1)(1) (2)(2) Shop (3)Shop (3) (4)(4) (5)(5) (6)(6)

Assembly (1)Assembly (1)

Painting (2)Painting (2)

Machine Shop (3)Machine Shop (3)

Receiving (4)Receiving (4)

Shipping (5)Shipping (5)

Testing (6)Testing (6)

Number of loads per weekNumber of loads per week

50 100 0 0 20

30 50 10 0

20 0 100

50 0

0





Room 1Room 1 Room 2Room 2 Room 3Room 3


4040

Receiving Shipping TestingDepartment Department Department

(4) (5) (6)


Assembly Painting Machine ShopDepartment Department Department

(1) (2) (3)


100100

5050

2020

5050

5050

20201010

100100

3030

Interdepartmental Flow GraphInterdepartmental Flow Graph

1 2 3

4 5 6




Cost = $50*20 + $100*40 + $20*60(1 and 2) (1 and 3) (1 and 6)

+ $30*20 + $50*40 + $10*20(2 and 3) (2 and 4) (2 and 5)

+ $20*60 + $100*20 + $50*20(3 and 4) (3 and 6) (4 and 5)

= $13,200

Cost = Xij Cijn

i = 1

n

j = 1





4040

Receiving Shipping TestingDepartment Department Department

(4) (5) (6)

Figure 9.8

Painting Assembly Machine ShopDepartment Department Department

(2) (1) (3)



3030

5050

1010

5050

202020205050 100100

100100

Revised Interdepartmental Flow GraphRevised Interdepartmental Flow Graph

2 1 3

4 5 6




Cost = $50*20 + $100*20 + $20*40(1 and 2) (1 and 3) (1 and 6)

+ $30*40 + $50*20 + $10*40(2 and 3) (2 and 4) (2 and 5)

+ $20*60 + $100*20 + $50*20(3 and 4) (3 and 6) (4 and 5)

= $10,600

Cost = Xij Cijn

i = 1

n

j = 1


Lower Cost Layout


Assembly Line Balancing

Objective is to minimize the imbalance between machines or personnel while meeting required output

Starts with the precedence relationships Determine cycle time Calculate theoretical minimum number of

workstations Balance the line by assigning specific tasks to

workstations Calculate efficiency


Cycle time = Production time available

Demand per day

Minimum number of work stations

Task timesCycle time

Efficiency =

=

Task times(Actual number of work stations)*(Largest cycle time)

Assembly Line Balancing


This means that tasks B and E cannot be done until task A has been completed

Performance Task Must FollowTime Task Listed

Task (minutes) BelowA 10 B 11 AC 5 BD 4 BE 12 AF 3 C,DG 7 FH 11 EI 3 G,HTotal time 66

Copier Example



Task (minutes) BelowA 10 B 11 AC 5 BD 4 BE 12 AF 3 C,DG 7 FH 11 EI 3 G,HTotal time 66

I

GF

C

D

H

B

E

A10

1112

5

4 3

711 3

Figure 9.13

Copier Example


I

GF

C

D

H

B

E

A10

1112

5

4 3

711 3


Task (minutes) BelowA 10 B 11 AC 5 BD 4 BE 12 AF 3 C, DG 7 FH 11 EI 3 G, HTotal time 66

480 available mins per day

40 units required

Cycle time =Production time available per day

Units required per day= 480 / 40= 12 minutes per unit

Minimum number of

workstations= Time for task i

Cycle time

n

i = 1

= 66 / 12= 5.5 or 6 stations

Copier Example


I

GF

C

D

H

B

E

A10

1112

5

4 3

711 3

Copier Example

PerformancePerformance Task Must FollowTask Must FollowTimeTime Task ListedTask Listed

TaskTask (minutes)(minutes) BelowBelowAA 1010 BB 1111 AACC 55 BBDD 44 BBEE 1212 AAFF 33 C, DC, DGG 77 FFHH 1111 EEII 33 G, HG, HTotal time Total time 6666


40 units requiredCycle time = 12 mins

Minimum workstations = 5.5 or 6

Line-Balancing Heuristics

Choose the available task with the least number of following tasks

5. Least number of following tasks

Choose the available task with the shortest task time

4. Shortest task time

Choose the available task for which the sum of following task times is the longest

3. Ranked positional weight

Choose the available task with the largest number of following tasks

2. Most following tasks

Choose the available task with the longest task time

1. Longest task time

Table 9.4

Primary Rule

Secondary Rule





PerformancePerformance Task Must FollowTask Must FollowTimeTime Task ListedTask Listed

TaskTask (minutes)(minutes) BelowBelowAA 1010 BB 1111 AACC 55 BBDD 44 BBEE 1212 AAFF 33 C, DC, DGG 77 FFHH 1111 EEII 33 G, HG, HTotal time Total time 6666Station

1

Station 2

Station 4

Station 5

Station 3

Station 6

Figure 9.14

Copier Example

5

I

GF

H

C

D

B

E

A10 11

12

4

3 7

11

3





Efficiency = Task times

(actual number of workstations) x (largest cycle time)

= 66 minutes / (6 stations) x (12 minutes)= 91.7%

Copier Example

I

GF

C

D

H

B

E

A10

1112

5

4 3

711 3

05 - layout strategy

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