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( 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
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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)
=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
; I '0 07 B
B 0 0+ K
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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
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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)
=or. Station %as. %as. %ime %ime 4emainingFeasi"le tas.s
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 ===
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, 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
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,,(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
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( ,(
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'0'(
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%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
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e L,(07
,+
*(*),)
0'777percentdle ==
+++=
:*(*),)
6,A ==
6 a
)'#(*
Positional weights
in parentheses
6-'9
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)+9*
0(
)+7*
09
)+6*
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C% 8 '
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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)
=or. Station %as. %as. %ime %ime 4emainingFeasi"le tas.s
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 ==
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: 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
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B ( (9
' '9
@ 0 '0
QPositional weight
C% 8 0 seconds
6-('
! 3 C
A
B
I
F
@
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Chapter 06 - Process Selection and Facility Layout
=or. Station %as. %as. %ime %ime 4emainingFeasi"le tas.s
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
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Chapter 06 - Process Selection and Facility Layout
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-(+
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Chapter 06 - Process Selection and Facility Layout
=or. Station %as. %as. %ime %ime 4emainingFeasi"le tas.s
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-(,
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(
+
,
6
!
R
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o
!
R
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o
o
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o
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Chapter 06 - Process Selection and Facility Layout
'( + ' , 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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Chapter 06 - Process Selection and Facility Layout
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
, -
6-(6
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Chapter 06 - Process Selection and Facility Layout
%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
6-(:
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Chapter 06 - Process Selection and Facility Layout
'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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Chapter 06 - Process Selection and Facility Layout
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*
=or. Station %as. %as. %ime %ime 4emainingFeasi"le tas.s
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# # @
6-(9
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Chapter 06 - Process Selection and Facility Layout
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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Chapter 06 - Process Selection and Facility Layout
!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