Filled Notes for Chapter 6

8/10/2019 Filled Notes for Chapter 6

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Chapter 06 - Process Selection and Facility Layout

( 5uality is chec.ed during different stages of the production process

a Chec. salt for purity using chemical analysis

" !ssure appropriate crystal si$e "y forcing the salt through a scraping screen

c 4emove the small pieces of metal "y magnets at different stages of the process

d Chec. the weight of the filled cans# attach the la"el stic.er

e Chec. to ma.e sure that metal pour spouts are correctly attached

+ %he company may not have updated its equipment "ecause of the high cost of investment innew machinery

, Salt production would "e a low variety# high volume operation which would place it as arepetitive production or continuous flow in the product-process matri

)+#700#000 cans per year* )(6 ounces of salt per can* 8 97#700#000 ounces per year

)97#700#000 ounces per year* / )'6 ounces per pound* 8 6#':#000 pounds per year

)6#':#000 pounds per year* / )(000 pounds per ton* 8 +#07: tons of salt per year

6 Suggested improvements include the following&

a !pplication of Statistical Process Control )SPC* to reduce the cost of quality

" evelop a plan to overhaul the eisting equipment and to purchase new equipment as a2oint effort among finance# purchasing and manufacturing areas

c Synchroni$e production# distri"ution and capacity planning to ma.e sure that there issufficient capacity in the silos to handle the incoming salt from "rine production

Rea$ing! Tor De Force

' %he ;iper/Prowler assem"ly plant is much smaller than typical automo"ile assem"ly plants%he plant covers +9(#000 square feet of space as opposed to other typical auto assem"ly plants

that cover from ( million square feet to million square feet of space

%he production capacity of the ;iper plant is much less than a typical automo"ile assem"lyline %he ;iper plant


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( %he reasons for not having ro"ots or other high level automation include the following&

Chrysler Corporation wants to portray a high quality image of two handcrafted automo"ilemodels that is generally more epensive and appealing to high-income individuals %hepersonal attention to the customers is part of the mar.eting pac.age associated with "othproducts

%he company also wants to draw attention to this facility and the two car models );iper andProwler* manufactured at this facility "ecause it is an unusual and attractive automo"ilemanufacturing facility Chrysler Corporation is hoping that not only will it draw attention tothe two hand-crafted automo"ile models produced within the facility "ut also possi"lyimprove the general goodwill associated with the company

Rea$ing! Designing Sper%ar&ets

%his reading provides the student with an eample of how a supermar.et is laid out and why thearrangement is done in a particular or specific way t is a nice change of pace from the typical

manufacturing layout article

Ans'ers to Discssion an$ Re(ie' )estions

' Process selection refers to the ways organi$ations choose to produce or provide their goodsand services t involves choice of technology# type of processing# and so on %hese choiceshave important implications for capacity planning# layout of facilities# equipment choices# andthe design of wor. systems

( %here are five "asic process types&

a @o"-shop& @o"-shop is used when a low volume and a large variety of goods or services areneeded @o"-shop involves intermittent processing# high flei"ility# s.illed wor.ers#relatively large wor.-in-process inventories and general-purpose machinery !n eampleis a tool and die shop that is a"le to produce a wide variety of tools

" 3atch& 3atch processing is used when a moderate volume of goods and services isdemanded t is designed to handle a moderate variety in products %he processing isintermittent %he flei"ility of the process to produce a variety of goods# the s.ill of thewor.ers# amount of wor.-in-process inventories are all less than 2o" shop ! typicaleample of "atch processing is paint manufacturing

c 4epetitive& %his type of a process involves higher volumes of more standardi$ed goods or

services %he flei"ility of the process to produce a variety of goods# the s.ill of thewor.ers# amount of wor.-in-process inventories are all less than "atch process %ypicaleamples for this type of process include appliances and automo"iles

d Continuous& %his type of a process involves very high volume of highly standardi$edgoods or services %hese systems have no flei"ility in output or equipment =or.ers aregenerally low s.illed and there is no wor.-in-process inventory %he machines arededicated to perform specified tas.s %ypical eamples include petroleum products# steeland sugar manufacturing

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e Pro2ect& Pro2ects are designed to "e used with non-routine# unusual tas.s or activities%hese activities are generally not repeated Aquipment flei"ility# level of wor.er s.illsand wor.-in-process inventory can range from very low to very high Aamples includeconstruction of a dam or a "ridge# conversion of the production system from 2o"-shop to

group technology# installing and implementing a new inventory and "ar coding system+ !dvantages& Bighly uniform output# "oredom and fatigue are not factors# machines don


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g For a product layout# the flow of wor. is straight# while for process layout# the flow ofwor. is mied depending on the product produced

h %here is more dependency "etween wor.stations for product layout than for a processlayout

i %he preventive maintenance and machine relia"ility are more important in a productlayout than process layout "ecause equipment "rea.down may involve shutting down awor. station which may in turn result in shutting down downstream wor. stations

2 4outing and scheduling is much less complicated for processes with product layout thanprocesses with process layout

9 %he most common reasons for redesign of layouts include&

a nefficient operations

" !ccidents or safety ha$ards

c Changes in the design of products or services

d ntroduction of new products or services

e Changes in the volume of output or mi of outputs

f Changes in methods or equipment

g Changes in environmental or other legal requirements

h 1orale pro"lems

'0 Product layoutsare generally characteri$ed "y speciali$ed la"or and equipment designed forcontinuous processing %he layout is often arranged on the "asis of processing sequenceProcess layouts are more general in nature# in terms of la"or# processing equipment andmaterial handling equipmentProcess layoutsoften feature machine groups or departments

tems processed in process layouts tend to follow differing paths through the systemFixedposition layoutsare used to facilitate processing of a single )usually large* 2o"# such asconstruction of a large "uilding or a hydro-electric power plant La"or# equipment andmaterials are typically "rought to the 2o" site )ie# to the >product?* rather than the other wayaround Fied position layouts are commonly found in farming# road "uilding# homeremodeling and mining

'' %he main advantages of product layouts include&

a ! potentially high rate of output

" Low unit costs

c Low training costs and wide span of supervision due to speciali$ation

d Low unit cost for material handling

e Bigh utili$ation of la"or and equipment

f 4outing and scheduling are "uilt into the design

g !ccounting# purchasing and inventory control are fairly routine

%he main disadvantages of product layouts include&

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a Speciali$ation can mean dull# repetitive 2o"s with little opportunity for personalsatisfaction or creativity

" =or.ers may have little interest in maintaining equipment or in the quality of output

c %he system is not particularly adapta"le to changes in process design or changes in thevolume of output

d %he system is highly suscepti"le to shutdowns caused "y equipment failure or ecessivea"senteeism

e Preventive maintenance costs and the capacity for quic. repairs are necessary to ensurehigh utili$ation

f ncentive plans tied to individual output are impractical

'( %he main advantages of process layouts are&

a %hey can handle a variety of processing requirements

" %he system is less vulnera"le to equipment failures than product layoutsc %he general purpose equipment used is often less costly than the speciali$ed equipment

used in product layouts t is also usually easier and less costly to maintain and repair

d ndividual incentive systems are possi"le

%he main disadvantages of process layouts are&

a n-process inventory costs can "e high )manufacturing*

" 4outing and scheduling must "e done for each new 2o"

c Aquipment utili$ation rates are usually low

d 1aterial handling is slower# less efficient# and more costly per unit than with a product

layoute %here is often a lower span of supervision compared to a product layout

f nit costs tend to "e higher than compara"le output produced with a product layout

g !ccounting# inventory control and purchasing are generally more involved than with aproduct layout

'+ %he main goal of line "alancing is to achieve a set of tas. groupings at wor. stations in theline that have equal time requirements in order to get a high utili$ation of la"or andequipment n"alanced lines have "ottlenec.s at some wor. stations and idle time at others%he resulting output is lower than it would "e if the line were "alanced

', 4outing and scheduling are continual pro"lems in a process layout "ecause a variety of 2o"s

pass through the system# and they tend to differ in terms of routing and schedule requirementsn contrast# product layouts typically handle items with little or no varietyGall have the sameor similar routing and scheduling requirements

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' =ith a product layout# equipment "rea.down has serious implications "ecause the separatepieces of equipment are closely tied together f one piece of equipment fails# the line willquic.ly come to a halt Consequently# preventive maintenance to reduce the failure rate isadvisa"le n contrast# a process layout often contains duplicative equipment so that if one

particular piece of equipment fails# the wor. can usually "e shifted to another piece ofequipment Consequently# there is less need for preventive maintenance# and less need forrepair of equipment when it does "rea. down 1oreover# process layouts utili$e more s.illedwor.ers who tend to ta.e "etter care of the equipment than their lower s.illed counterparts ina product layout system

'6 @o" sequence usually determines the arrangement of equipment in a product layout n aprocess layout# 2o" sequences vary# so there is much less influence on equipment arrangement3ecause of differences in 2o" requirements# sequencing is a continual tas. in a process layout

': %he su"way system is essentially a fied-path arrangementGa product layout ts advantagesare often low operating cost# more efficient handling# and low cost per unit moved Hn theother hand# a "us system is more flei"le in terms of varying routes %his can "e desira"le if

there are shifts in which potential riders are coming from and going to For eample# a new"us route could easily "e esta"lished to service a new shopping area# a new apartmentcomple# or a large industrial facility Hther considerations are initial cost )high for su"wayand relatively low for "us*# severity of difficulties that would arise from a "rea.down )high forsu"way# low for "us*# the possi"ility of alternative uses )none for su"way# private groups# etc#for "us during off times*# and possi"le disruptions caused "y weather )higher ris. for "us thansu"wayGeg# snowstorms stall highway traffic*

'7 Fied-path material handling equipment in supermar.ets includes the "elts at the chec.outswhich move items up to the cashier# the roller conveyors which transport "oes of groceriesoutside to pic.up areas# conveyors in the meat department to move carcasses from storage tocutting ta"les# roller conveyors to off-load goods from truc.s and move them to storage;aria"le-path material handling equipment includes grocery carts# >truc.s? and >2eeps? used

to transport "a.ed goods from storage to display shelves# and mova"le rac.s to transport"a.ed goods from ovens or from deliveries to the "a.ery counter

'9 Beuristic approaches are rules designed to guide decision-ma.ers tosatisfactorydecisions "yreducing the num"er of alternatives that must "e considered %hey do not necessarily yieldoptimal solutions %hey are usually employed when there is a pro"lem involving aneceedingly large num"er of potential solutions andan optimi$ing algorithm is not availa"le

(0 onmanufacturing environments do not usually lend themselves to product layouts "ecausethey tend to involve more processing variety than many manufacturing environments

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(' %he original car was pro"a"ly one of a large num"er of similar cars produced on an assem"lyline# which was set up to speed the flow of wor. %hat is# inventories of parts were on hand#speciali$ed machinery# wor.ers and material handling equipment were arranged specificallyfor the 2o" !s a result of this continuous processing# the unit cost of the car was relatively

low n contrast# constructing a car from >scratch? is essentially a cross "etween intermittentprocessing and a pro2ect# with none of the economies of continuous processing ! list of theparts must "e assem"led Some might "e availa"le locally# "ut others would have to "eshipped individuallyfrom suppliers %he parts would have to "e held until all were on hand=or.ers would not "e highly familiar with this particular car# even though they wereeperienced in this sort of wor. Consequently# the wor. would progress at a fairly slow rate#and pro"a"ly with a certain amount of "ac.-trac.ing H"viously# construction of areplacement would "e considera"ly more costly than initial# continuous production

(( Layout can lead to high productivity if it contri"utes to a smooth flow of wor. with highutili$ation of la"or and equipment %his requires careful consideration of future wor.requirements to determine what will "e needed and a certain amount of effort to o"tain anoptimal )or satisfactory* layout ! poor layout will hinder productivity with "ottlenec.s# lower

utili$ation of la"or and equipment than is necessary# and require more handling or movement"etween wor. stations than is necessary )particularly in process layouts*

(+ n cellular manufacturing# machines are grouped into cells %he "asis for grouping can "eoperations needed to process a group of similar items or part families !dvantages of suchsystems include relatively short throughput time# reduced material handling# less wor.-in-process inventory# and reduced setup time

(, Iroup technology involves items that have similar design or processing requirements andgrouping them into part families for cellular manufacturing t also includes a coding systemfor items

( !lthough we treated the tas. completion times as fied in "alancing assem"ly lines# it is more

realistic to assume varia"le tas. times whenever humans are involved %he lower the level ofautomation# the higher the varia"ility of tas.s f the assem"ly line consists of tas.s withvaria"le completion times# it will "e more difficult to "alance the line n order to deal withvaria"ility of tas. times# we can require a minimum amount of slac. to "e availa"le at eachwor.station !s the varia"ility of tas. times increase we can increase the minimum slac.availa"le at each wor.station n addition# wor.station slac. time can also "e used for sloweror less eperienced wor.ers who ta.e longer than normal to complete a tas.

Ta&ing Stoc&

' %he three ma2or trade-offs in process selection are&

a Flei"ility vs efficiency in facilities layout Product layout is designed to provide efficient

operations# while process layout is designed to provide a variety of products# thus offeringa flei"le system

" Level of automation )high vs low* Bigh level of automaton has the potential advantage ofproviding faster production or service# the a"ility to quic.ly switch from product toproduct resulting in higher flei"ility Hn the other hand# high level of automationinvolves higher cost and the potential ris. that it may involve costly implementationpro"lems

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c %he epected volume of output can either "e high or low f it is high# we can ta.eadvantage of the economies of scale and reduce costs and improve efficiency Bowever# ifwe ma.e a commitment to high volume production and the demand is consistently low#we may "e faced with the potential pro"lem of low efficiency and low utili$ation of the

machines and idle resources Hn the other hand# if the epected volume is low# then wepro"a"ly have decided to compete as a 2o"-shop# emphasi$ing flei"ility f there is acapacity-demand mismatch# we will either have too few resources allocated for productionor we will have a capacity constraint on resources

( f we re"alance the assem"ly line too frequently# then the cost of ma.ing the ad2ustments"ecomes too costly Hn the other hand# if we do not re"alance it as frequently as necessary#then the assem"ly line will eperience too much inefficiency resulting in a less efficient line

+ n process selection# we must ma.e sure that manufacturing group)s*# maintenance#engineering# technical support# mar.eting# process design specialists# quality# finance)especially if we need capital to support the facility layout# new equipment or new machinery*are involved Hf course we also need to ma.e sure that there is a representative from top

management to ensure that we stay consistent with the overall goals and o"2ectives of the firm, n layout design# we must ma.e sure that manufacturing group)s*# maintenance# engineering#

technical support# process design specialists# quality# finance )especially if we need capital tosupport the facility layout# new equipment or new machinery* are involved

%echnology has tremendous impact on process selection due to changes in computer relatedtechnology %he level of automation continues to change in companies affecting the layoutdecisions For eample# the newer machinery are smaller# therefore the si$e of the machineryaffects the wor. area si$e and ultimately the layout of the facility

Critica# Thin&ing E*ercises

' Student answers will vary( FactoriesGtype of machines# s.ill level of the employees# level of automation# inventories# safety

Supermar.etsGmaimi$ing sales potential# minimi$ing inventory investment# level ofautomation# type of automation# num"er of cashier lines# proimity and location of variousdepartments within the supermar.et

epartment storeGmaimi$ing sales potential# minimi$ing inventory investment# level ofautomation# type of automation# proimityGdistance and location of various departmentswithin the department store# capacity and convenience of the par.ing lot

+ Factors that must eist in order to ma.e automation feasi"le are&

a %he level of demand& %he demand must "e forecasted Ienerally# we need high volume of

output to 2ustify the high cost associated with automation

" %he degree of varia"ility required in the manufacturing or the service system& %he higherthe degree of varia"ility required# the less the chance of success for automation

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Strategic fit with the overall goals and o"2ectives of the company& f the type of automationdoes not lend itself to flei"le manufacturing# "ut the o"2ectives and goals of the companyinvolve low volume large variety of products# we could have significant capacity-demandmismatch pro"lems due to this misalignment

For production# the ris.s relate to the possi"ility that demand will increase# and it will "ecostly to ad2ust the process to meet that increase# or that it will decrease and leave ecesscapacity# and fewer units to a"sor" costs n addition# employee morale may suffer ifemployees fear losing 2o"s For service )eg# automated call center*# customers may prefertal.ing to an actual person# or the system may not "e a"le to handle the variety of requests ordemands from customers

"e%o +riting E*ercises

' n most cases it is not feasi"le to perfectly "alance a production line First# there are

technological constraints dealing with precedence and incompati"ility issues n other words#certain tas.s have to "e performed "efore others )precedence* and two tas.s may not "eperformed at the same station due to their incompati"ility )space and nature of operationconsiderations* Secondly# there are output constraints Since most tas. times vary# outputconstraint determines whether an otherwise eligi"le tas. will fit at a wor.station "ecause sumof the tas. times assigned to a station cannot eceed the cycle time !s a result of "othtechnological and output constraints# it is etremely difficult to achieve a perfectly "alancedproduction line %he larger the num"er of tas.s# the more difficult it is to achieve perfect"alance

( Producing two products on the same assem"ly line allows the company to utili$e thesame wor.stations to produce the common parts %his results in synergy on the line f one of

the products is new# the company can shorten the period of time from design to actualproduction# and reduce the cost of manufacturing in the long run

+ Fied automation is utili$ed in a continuous flow/mass production environment tena"les the firm to manufacture a single or a few products at high volume and low costBowever# it is not flei"le enough to produce a variety of parts and it is very costly to ma.echanges to the process Flei"le automation is utili$ed in a 2o" shop )intermittent*environment# where a wide variety of products can "e produced without significantchangeover )setup* time/cost Flei"le machinery is not designed for high volume )mass*production

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So#tions

' H% 8 ,0 minutes

a 1inimum cycle time 8 length of longest tas.# which is (, minutes

1aimum cycle time 8 tas. times 8 '7 minutes

" 4ange of output&

units('7

,0&min'7J

units'7:,(

,0&min,(J

=

=

c 7toroundswhich#:,0

*'7)'7:

H%

t- ==

=

d cycleperminutes6+'(

,0C%C%#forSolvingC%

H%Hutput ===

e Potential output&

)'* units09

,0

C%

H%&min9C% ===

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)(* units+0'

,0&min'C% ==

(

esired output 8 ++++ units per hour

Hperating time 8 60 minutes per hour

unitperminutes70'hourperunits++++

hourperminutes60

output-esired

timeHperatingC% ===

a

%as. um"er of following tas.s Positional =eight

! : 6

3 6 ,6

C ( '6

( ((

A ( (+

F ' '0

I ' '

B 0 0

6-'(

06

0:

07

0

'0

00',

c

f

h

g

d

e

"a


13/31


Assembly Line Balancing Table (CT = 1.8)

=or. Station %as. %as. %ime %ime 4emainingFeasi"le tas.s

4emaining

! ', 0, K

3 0 '+ C# # A

A 07 0 K

0: '' C

C 06 0 F

F 0 0 K

IV I '0 07 B

B 0 0+ K

" Assembly Line Balancing Table (CT = 1.8)


4emaining

! ', 0, K

3 0 '+ C# # A

A 07 0 K

0: '' C

C 06 0 F

F 0 0 K

; I '0 07 B

B 0 0+ K

6-'+


14/31


c L+7+(:

06

stationsofnoC%

time%otalAfficiency ===

+

esired output 8 ,

Hperating time 8 6 minutes

unitperminutes',hourperunits,

hourperminutes6

output-esired

timeHperatingC% ===

%as. D of Following tas.s Positional =eight

! , (+

3 + (0

C ( '7

+ (

A ( '7

F , (9

I + (,

B ' ',

0

6-',

+

a

d

f

:

(

"

,

c

,

e

9

h

i

6

g


15/31


a First rule& most followers Second rule& largest positional weight

Assembly Line Balancing Table (CT = 14)

=or. Station %as. %as. %ime %ime 4emaining

Feasi"le tas.s

4emaining

F 9 !##I

! + 6 3#I

I 6 K K

: : 3# A

3 ( C

C , ' K

A , '0 B

B 9 ' K

IV 9 K

" First rule& Largest positional weight

Assembly Line Balancing Table (CT = 14)


4emaining

F 9 !##I

: ( K

I 6 7 !# A

! + 3#A

3 ( + K

C , '0 A

A , 6 K

; B 9

K

c L+6706

,

stationsofnoC%

time%otalAfficiency ===

6-'


16/31


, a# "a l

( 1inimum Ct 8 '+ minutes

%as. Following tas.s

a ,

" +

c +

d (

e +

f (

g '

h 0

=or. Station Aligi"le !ssign %ime 4emaining dle %ime

a ! ''

"#c#e# )tie* 3 0:

C 0,

A 0+ 0+

d 00 00

f#g F 0

I 0( 0(

; h B 0' 0'

06

+ percent,''*+'),

6

C%

time*)idlepercentdle ==

=

6-'6

a " d

c

fe g

h


17/31


,,(0 min/day

+(+' ) +(+* /'+ min/

OTOutput rounds to copiers day

CT cycle= = =

" 'inutesm+(

(

,6

time%otalC%#6,time%otal ====

( !ssign a# "# c# d# and e to station '& (+ minutes Mno idle timeN

!ssign f# g# and h to station (& (+ minutes

+,(0

'7(6 copiers /(+

OTOutput day

CT= = =

,,(0 min/day

1aimum Ct is ,6 Hutput 9'+0 copiers /,6 min/

daycycle

= =

a

" %he minimum cycle time 8 maimum tas. time 8'( minutes

%he maimum cycle time 8 ( O, O( O, O'( O'( O '0 8 ,6 minutes

C%*d)calculateminutes(day/nitsu,0(

min/day,70

output

H%C% ===

c stations+*to)rounds+(0(

,6

C%

t ==

=

d

6-':

a "

d

cf

e

g

( ,(

'(

'0'(

,


18/31


%as. um"er of following tas.s

! ,

3 +

C (

(

A '

F '

I 0

Assembly Line Balancing Table (CT = 2 minutes)

=or. Station %as. %as. %ime %ime 4emaining Feasi"le tas.s4emaining

! 0( '7 3#

3 0, ', C#

0, '0 C

C 0( 07 K

A '( 07 K

F '( 07 K

; I '0 '0 K

6-'7


19/31


e L,(07

,+

*(*),)

0'777percentdle ==

+++=

:*(*),)

6,A ==

6 a

)'#(*

Positional weights

in parentheses

6-'9

0'

)+9*

0(

)+7*

09

)+6*

06

)(:*

0'

)((*

0(

)('*

0,

)'9*

0'

)'*

0(

)',*

0:

)'(*

a " c d

e f g h i 2

.

l

)0*

)0(*

0+

0(

C% 8 '


20/31


6 " sing "oth the greatest positional weight and the greatest num"er of following tas.s rulesresult in the following "alance

Assembly Line Balancing Table (CT = 1.5 minutes)


4emaining ! 0' ', 3

3 0( '( C

C 09 0+ A

A 0' 0( K

06 09 F

F 0( 0: I

I 0, 0+ B

B 0' 0(

0( K K

@ 0: 07

0+ 0 L

L 0( 0+ K

%otal idle time 8 0( O 0 O 0+ 8 0

c For positional weights and greatest num"er of following tas.s

L''''*')+

'000ratedle ==

6-(0


21/31


: a

" ===00

:)60*

-

H%C% 7, minutes 8 0, seconds )maimum cycle time*

1inimum cycle time 8 maimum tas. time 8 0 seconds )results in 0, units ofproduction*

c stations,or7++,0

'9+

C%

t ==

=

d

%as. um"er of followers QP=

! 6 '06

3 6'

C , 0

, '06

A + 6

F ( +0

I ( +'

B ( (9

' '9

@ 0 '0

QPositional weight

C% 8 0 seconds

6-('

! 3 C

A

B

I

F

@


22/31



4emaining

! , K

0 K K

3 '' +9 C# A

A (6 '+ C# F

C 9 , K

; I '( +7 B# F

F '' (: B

B '0 ':

9 7 K

; @ '0 ,0 K

e L7((**)0)

'9+' ==I

7

",00

(0 minutes(00

CT = =

6-((

a c e 2 . m

g h

d f i

"


23/31


Station %as.s %ime dle/%ime

' a#" '9 '

( c#d '9 '

+ e#f#i (0 0, g#h#2 '

.#m '( 7

'

c%as.s

Positional=eight

a 7

" ,6

c ,,

d ,(

e +(

f +

g '9

h '

i (

2 (0

. '(

m +

6-(+


24/31



4emaining

a ' "# c# d" ', ' K

c '( 7 d# e

d : '

f '0 '0 e# i

e i# g

i 0 K

; 2 7 '( g

g , 7 h

h + K

. 9 '' m

m + 7 K

%otal idle time 8 ' O ' O 0 O O 7 8 ' minutes

d 3alance delay& part " and c '/'0 8 '

9 ' , +

( 6

'' ' ,

+ 7 :

6 (

6-(,

'0'

(

+

,

6

!

R

o

o

!

R

o

o

o

o

!

o

o

oo


25/31


'( + ' , 7Hr

' , 7Hr

' , 6

( : 6 + ( : 6 + ( : 7

' : 7Hr

+ ' : 7Hr

+ ' , 6

+ ( , 6 ( , 6 ( : 7

+ ' : 6Hr

' : 6

( , 7 + ( , 7

'+ + ' 7

9 : ,

( 6

', a First ran. or arrange the num"er of trips from high to low

epartment um"er of trips

(, 90

', 70

+,

(+ ,0

From this we can see that departments ( and , have the greatest interdepartmental wor. flow#so they should "e close# perhaps locations C and 3 et# we can see that the wor. flows for 'and ,# and + and , are high %herefore department , has to "e located at a central location)location 3*# while department ( is in location C# department ' is in location !# anddepartment + is in location

6-(


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istance Q um"er of trips matri

epartment ' ( + ,

' K )'0 70* 8 700 )(0 :0* 8 ',00 )70 ,0* 8 +(00

( K K ),0 60* 8 (,00 )90 ,0* 8 +600+ K K K ) 0* 8 (:0

, K K K K

%otal cost 8 ',#'0

"

A

#2

B

#4

C

#3

D

#1

epartment ' ( + ,

' - (0 :0 8 ',00 (0 60 8 '(00 ,0 0 8 (000

( - '0 70 8 700 0 ,0 8 (000

+ - 60 ,0 8 (,00

, -

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%otal Cost 8 9#700

' o of trips)two way*

Hrder of!ssignment

'K( '0

'K+ ! reasona"le )intuitive* set of assignments is&

'K, 90 ''

'K +:0 ' !D'

3D'K6 '+ 6

'K: '( : CD:

D,

AD+'K7 0

(K+ +60 ( FD6

ID(

BD7(K, '(0 7 )tie*

(K ,0

(K6 '' 9 %his set of assignments has a total cost of ',+#60per day(K: ,

(K7 '(0 7 )tie*

+K, +0 + Slight variations would also "e reasona"le# as long asdepartments (# , and 7 are close to +# , is close to #and is close to '

+K ''0 '0

+K6 ,0

+K: (0

+K7 (00 ,

o of trips

)two way*

Hrder of

!ssignment,K '90 )tie*

,K6 :0 '(

,K: 0

,K7 '90 )tie*

K6 '0

K: ,0

K7 '0

6K: 0

6K7 (0

:K7 (0

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'6o of trips)two way*

'K( 0

'K+ ,0 ! reasona"le )intuitive* assignment is&

'K, ''0 +K!# K3# 'KC# ,K# 6KA# (KF

'K 70 !n equivalent solution is the reverse order&

'K6 0 (KF# 6K3# ,KC# 'K# KA# +KF

(K+ 0

(K, 0

(K ,0

(K6 '(0

+K, '0

+K (0

+K6 '0

,K ,0

,K6 90

K6 (0

)gnore 4eception since all locations are the same distance from it*

': %wo-way trips can not "e used here "ecause of the one-way route restrictionConsequently# students are forced to develop a heuristic that will yield reasona"leassignments Hne possi"le heuristic is the following&

3eginning with epartment '# identify the department which receives the greatest num"erof trips from that department )eg# ,0 to epartment (* !ssign that department to thenet location counter-cloc.wise

For that department )eg# (* identify the department which receives the greatest num"er oftrips )eg# * and assign it to the net position

Continue in this manner until all departments have "een assigned

%he resulting set of assignments for this pro"lem is& !K'# (K3# KC# ,K# 9KA# 7KF# 6KI# '0KB# :K# +K@

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Students may raise the question a"out return trips to the original departments after delivery#which would seem to ma.e all locations compara"le %hree possi"le eplanations are&

' 4eturn trips cost less "ecause they are unloaded

( nloaded trips may "e permitted to move cloc.wise+ 1aterial handlers )T* pic. up new load at each new department and move it to

the net department

)%he last eplanation seems to appeal most to students*


4emaining

0 0, K

! , , K

A (6 (, 3 #F

3 '' '+ C# F

F '' (, K

; C 9 ,' I# B

I '( (9 B

B '0 '9

9 '0 @

@ '0 0,

18. Station %as. ' ( ! + A# 3# F , C# I# B# # @

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Enrich%ent "o$#e! Process Design an$ Faci#it, La,ot Pro-#e%

!b"$!% lay!ut %&!blem

onald 4ice sold the "uilding that housed the restaurant/lounge he owned and operated for the last '0years and has recently purchased a larger "uilding in a new location 1r 4ice hopes to operate a newrestaurant and epand his growing "usiness %he "uilding has four equal si$e rooms onald


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!luti!n !* +&!blem 1

a Distance L!a 'at&i

%o

ining Lounge itchen Storage

ining K Q(#:00 QQ(#000 QQQ+0From Lounge K (#,00 (00

itchen K (#000

Storage K

Q ), 60* 8 (#:00

QQ)( 70* 8 (#000

QQQ)+ '0* 8 +0

%otal distance 8 (#:00 O (#000 O +0 O (#,00 O (00 O (#000 8 9#60 feet

" %he o"2ective is to arrange the departments such that the departments with high

interdepartment movements )D of trips* are close to one anotherSince the num"er of trips "etween .itchen and storage is the highest and room + and room ,)'00* have the closest proimity )shortest distance of '0 feet*# we will place .itchen andstorage in rooms + and , Bowever# at this point we have not decided which of the twodepartments will "e placed in room ' and room (

=e can o"serve that the net highest num"er of trips is "etween dining and .itchen )70* naddition# the shortest distance from rooms ' and ( to rooms + and , is (0 feet )room ( to room,* %herefore# .itchen is placed in room ,# storage is placed in room +# dining is placed inroom ( and the lounge is placed in room ' %he summary of the room assignments are given"elow&

4oom 'GLounge

4oom (Gining

4oom +GStorage

4oom ,Gitchen

,%ate (Distance) (L!a) 'at&i

%o

ining Lounge itchen Storage

ining K Q'#00 QQ'#600 QQQ600

From Lounge K '#,00 900

itchen K '#000Storage K

Q ), 60* 8 (#:00

QQ)(0 70* 8 '#600

QQQ)60 '0* 8 600

4evised total distance 8 '#00 O '#600 O 600 O '#,00 O 900 O '#000 8 :#000 feet

4eduction in total distance 8 9#60 K :#000 8 (#60 feet

Filled Notes for Chapter 6

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