7/25/2019 Review Questions Session 2

1/2

ReviewQuestionsSession2

A

four

stage

process

Theprocessingtimesforthemachinesshowninthefourstageprocessbelowareasfollows(in

minutes): W1:9,W2:9,M1:6,D1:5,G1:8andG2:12.

(a)WhatistheminimumTT,i.e.,ifacustomerrequiresarushorderhowfastcanyoudeliverit?

(b)Whatisthehourlycapacityforeachstage?

(c)Identifythebottleneckstageandtheprocesscapacity.

(d)Supposeyoucanaddonlyonemachineinparallelatthebottleneckstage. Amachinewithhigher

capacitycostsmore. Youwanttobuytheleastexpensivemachine. Whatshouldbethecycletime

forthenewmachinesothatyouincreasetheprocesscapacityasmuchaspossible?

Luis

Poisson

LuisPoissonisaParisbasedmanufacturerofluxuryleatherbags.Themanufacturingprocessfor

theirnewflagshipproductiscomposedof5fullyautomatedstations,asillustratedinfigure1below.

Thetheoreticalprocessingtimes(inminutes)forallthemachinesusedineachofthe5stationsare

alsoreportedinthefigure.

Figure 1: Luis Poissons manufacturing process

1.

Whatis

the

average

Throughput

Rate

of

the

process

(in

units/hour)?

2. WhatistheMinimumThroughputTime(inminutes)?

3. Whichstationistheprocessbottleneck?

W1

9min

W2

9min

D1

5min

G1

8min

G2

12min

F1

M1

6 min

7/25/2019 Review Questions Session 2

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Eric

&

Old

YouarepartoftheoperationsmanagementteamatEric&Old,amajorconsultingcompany.

AsafirstassignmentyourgroupisbroughtintohelpRodiimprovetheircustomerresponsetimesto

theirnewcustomersintheautomobileindustry.Rodimanufacturescomponentsforairplanesand

motorvehicles.Untilnow,theyhavemostlyworkedinthedefensesector,wherecustomersare

moreconcernedwithtechnologyandqualitythanwithresponsetime.Inthenewenvironment

responsetime

and

production

cost

are

much

more

important

and

have

become

akey

priority

to

them.

Rodisproductionsystemisorganizedasamaketoorderserialproductionline.Becauseofthe

variabilityinthetypesandquantitiesofproductsorderedbytheircustomersandbecausesetups

areoftenrequiredbetweendifferenttypesofproductstheydonotutilizeanassemblyline.Instead

theyproduceinbatchesthataretriggeredbycustomerorders.

Onyourfirstvisit,themanagersexplainthatinordertocontrolcost theyhavetriedtoincrease

theutilizationratesofsomeoftheirequipments.Specifically,theynoticedthatoneofthe

workstationsneartheendoftheproductionlinehadonly60%utilization.Theyfeltitmaybeoneof

theupstreamstations(onethatiscurrentlyutilizedbymanydifferenttypesofjobs)thatis

interferingwiththeutilizationrateofthismachine.Thisupstreamworkstation, infact,causesmany

problemsattheirplant,oneofwhichisthatovertimeisfrequentlyscheduledonweekendsto

reduce

the

numbers

of

jobs

waiting

in

front

to

it

for

processing.

Tomaximizeutilizationatthedownstreammachine,theyhavedecidedtomakesurethatjobs

destinedfortheunderutilizeddownstreamworkstationwouldhavepriorityatthisupstream

station.Theywouldevenbreaksetupsontheupstreammachinewhenthedownstreamworkstation

wasindangerofrunningoutofwork.

Asaconsultantwhatdoyoutellthemabouttheircurrentresponsetotheproblemsfaced?Whatis

theimpactofthenewpolicyonthedownstreamutilizationrate?Whatistheimpactonthe

upstreamutilizationrate?

Itwillimprovethesituation Itwillhavenoeffect Itwillworsenthesituation

Why?