Chapter 7A Operations Management 2010 Class Notes

7/30/2019 Chapter 7A Operations Management 2010 Class Notes

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Facility Layout and Basic Formats

Process Layout

Layout Planning

Assembly Line balancing

Service Layout

OBJECTIVES

Chapter 7A Facility Layout


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Facility Layout

Facility layout can be defined as the process by which the

placement of departments, workgroups within departmworkstations, machines, and stock-holding points withfacility are determined

This process requires the following inputs:

Specification of objectives of the system in terms of oand flexibility

Estimation of product or service demand on the system

Processing requirements in terms of number of operatand amount of flow between departments and work ce

Space requirements for the elements in the layout

Space availability within the facility itself


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Basic Production Layout Formats

Process Layout (also calledjob-shopor

func t ional layou t)

Product Layout (also called f low-shop la

Group Technology (Cellular) Layout

Fixed-Position Layout


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Process Layout: I nterdepartmental F low

Given

The flow (number of moves) to and from all depa

The cost of moving from one department to anot

The existing or planned physical layout of the pla

Determine

The best locations for each department, wheremaximizing flow, which minimizing costs


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Process Layout: CRAFT Approach

It is a heuristic program; it uses a simple rule o

in making evaluations: "Compare two departments at a time and ex

them if it reduces the total cost of the layou

It does not guarantee an optimal solution

CRAFT assumes the existence of variable pathhandling equipment such as forklift trucks


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Process Layout: Systematic Layout Planning

Numerical flow of items between departments

Can be impractical to obtain

Does not account for the qualitative factors that may

the placement decision

Systematic Layout Planning

Accounts for the importance of having each departmnext to every other department

Is also guided by trial and error

Switching departments then checking the results

closeness score


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Example of Systematic Layout Planning:

Importance of Closeness

Value

A

E

I

OU

X

ClosenessLine

code

Num

weAbsolutely necessary

Especially important

Important

Ordinary closeness OKUnimportant

Undesirable


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Relating Reasons and Importance

From

1. Credit department

2. Toy department

3. Wine department

4. Camera department

5. Candy department

6

I

--

U

4

A

--

U

--

U

1

I

1,6

A

--

U

1

X

1

X

To

2 3 4 5

A

(s

Closeness rating

Reason for rating

Letter

Number


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Initial Relationship Diagram

1

2

4

3

5

X X

E

A

I

The number of li

represent paths r

be taken in trans

between the depa

The more lines, tinteraction betwe

departments.Note here again, Depts. (1) and (2) are

linked together, and Depts. (2) and (5)

are linked together by multiple lines

or required transactions.


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Initial and Final Layouts

1

2 4

3

5

Initial Layout

Ignoring space and

building constraints

2

5 1 43

50 ft

20 ft

Final Layout

Adjusted by square

footage and building

size

Not

Lay

Dep

are

plac

nex


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Example of Line Balancing

Youve just been assigned the job a setting up an electric fan

line with the following tasks:

Task Time (Mins) Description

A 2 Assemble frame

B 1 Mount switch

C 3.25 Assemble motor housing

D 1.2 Mount motor housing in frame

E 0.5 Attach bladeF 1 Assemble and attach safety grill

G 1 Attach cord

H 1.4 Test


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Example of Line Balancing:

Structuring the Precedence Diagram

Task Predecessors Task PredecessorsA None

B AC None

D A, C

E D

F E

G B

H F, G

A B

C D E F

G

H


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Example of Line Balancing: Precedence Diagram

A

C

B

D E F

GH

2

3.25

1

1.2 .5

11.4

1

Question: Which process step defines the maximum rate of

production?

Answer: Task C is the cycle time of the line and therefo

the maximum rate of production.


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Example of Line Balancing:Determine Cycle Time

Question: Suppose we want to assemble 100 fans pe

What would our cycle time have to be?

periodperoutputRequired

periodpertimeProduction=CTime,CycleRequired

mins/unit4.2=units/day100

mins/day420=C


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Example of Line Balancing: Determine Theoret

Minimum Number of Workstations

Question: What is the theoretical minimum number of

workstations for this problem?

(C)timeCycle

(T)stask timeofSum=N

N

t

tns,WorkstatioofNumberMin.lTheoretica

3or2.702,=mins/unit4.2

mins/unit11.35=N t


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Rules To Follow for Loading Workstations

Ass ign tasks to stat ion 1, then 2, etc. in sequenc e. Keep a

wo rkstat ion ensur ing that precedence is m ainta ined and tless than or equal to the cycle t ime. Use the fol low ing rul

tasks for ass ignm ent .

Primary:Assign tasks in order of the largest number of fo

Secondary (t ie-breakin g):Assign tasks in order of the longoperating time


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A

C

B

D E F

GH

2

3.25

1

1.2 .5

11.4

1

C (4.2-3.25)=.95

Idle = .95

D (4.2-1

E (3-.5)=

F (2.5-1)

H (1.5-1

Idle = .1

Task Followers

A 6

C 4

D 3

B 2

E 2

F 1G 1

H 0

A (4.2-2=2.2)

B (2.2-1=1.2)

G (1.2-1= .2)

Idle= .2

Station 1 Station 2 Stat

Which station is the bottleneck? What is the effective cycle time?


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Determine the Efficiency of the Assembly Line

tCyclex(Na)onsworkstatiofnumberActual(T)stask timeofSum=Efficiency

901.=

s/unit)(3)(4.2min

mins/unit11.35=Efficiency


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Retail Service Layout

Goal--maximize net profit per square foot of floor

Servicescapes

Ambient Conditions

Spatial Layout and Functionality

Signs, Symbols, and Artifacts


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Baldwin Filter TourApril 14 & 15, during regular class time.

Bring the RPA sheet. You must take the tour before you can writ

Enter here Park here


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Baldwin Filter LocationPhone: (8

(

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Chapter 7A Operations Management 2010 Class Notes