.

/

Chapter02-Competitiveness,Strategy,andProductivity

3.

<1>

<2>

<3>

<4>

<5>

<6>

<7>

Week

Output

WorkerCost@

$12x40

OverheadCost@1.5

MaterialCost@$6

TotalCost

MFP<2><6>

1

30,000

2,880

4,320

2,700

9,900

3.03

2

33,600

3,360

5,040

2,820

11,220

2.99

3

32,200

3,360

5,040

2,760

11,160

2.89

4

35,400

3,840

5,760

2,880

12,480

2.84

*refertosolvedproblem#2

Multifactorproductivitydroppedsteadilyfromahighof3.03toabout2.84.

4. a. Before:805=16cartsperworkerperhour.

After:844=21cartsperworkerperhour.

b. Before:<$10x5=$50>+$40=$90;hence80÷$90=.89carts/$1.

After:<$10x4=$40>+$50=$90;hence84÷$90=.93carts/$1.

c. Laborproductivityincreasedby31.25%<<21-16>/16>.

Multifactorproductivityincreasedby4.5%<<.93-.89>/.89>.

*MachineProductivity

Before:80÷40=2carts/$1.

After:84÷50=1.68carts/$1.

Productivityincreasedby-16%<<1.68-2>/2>

Chapter03-ProductandServiceDesign

6. StepsforMakingCashWithdrawalfromanATM

1. InsertCard:MagneticStripShouldbeFacingDown

2. WatchScreenforInstructions

3. SelectTransactionOptions:

1> Deposit

2> Withdrawal

3> Transfer

4> Other

4. EnterInformation:

1> PINNumber

2> SelectaTransactionandAccount

3> EnterAmountofTransaction

5. Deposit/Withdrawal:

1> Deposit—placeinanenvelope<whichyou’llfindnearorintheATM>andinsertitintothedepositslot

2> Withdrawal—liftthe"WithdrawalDoor,"beingcarefultoremoveallcash

6. Removecardandreceipt<whichservesasthetransactionrecord>

8.

Technical

Requirements

Ingredients

Handling

Preparation

CustomerRequirements

Taste

√

√

Appearance

√

√

√

Texture/consistency

√

√

Chapter04-StrategicCapacityPlanningforProductsandServices

2.

Actualoutput=.8<Effectivecapacity>

Effectivecapacity=.5<Designcapacity>

Actualoutput=<.5><.8><Effectivecapacity>

Actualoutput=<.4><Designcapacity>

Actualoutput=8jobs

Utilization=.4

10. a. Given: 10hrs.or600min.ofoperatingtimeperday.

250daysx600min.=150,000min.peryearoperatingtime.

Totalprocessingtimebymachine

Product

A

B

C

1

48,000

64,000

32,000

2

48,000

48,000

36,000

3

30,000

36,000

24,000

4

60,000

60,000

30,000

Total

186,000

208,000

122,000

Youwouldhavetobuytwo"A"machinesatatotalcostof$80,000,ortwo"B"machinesatatotalcostof$60,000,orone"C"machineat$80,000.

b. Totalcostforeachtypeofmachine:

A<2>:186,000min60=3,100hrs.x$10=$31,000+$80,000=$111,000

B<2>:208,00060=3,466.67hrs.x$11=$38,133+$60,000=$98,133

C<1>:122,00060=2,033.33hrs.x$12=$24,400+$80,000=$104,400

Buy2Bs—thesehavethelowesttotalcost.

Chapter05-ProcessSelectionandFacilityLayout

3

a

d

f

7

5

2

b

4

c

4

e

9

h

5

i

6

g

3.

Desiredoutput=4

Operatingtime=56minutes

Task

#ofFollowingtasks

PositionalWeight

A

4

23

B

3

20

C

2

18

D

3

25

E

2

18

F

4

29

G

3

24

H

1

14

I

0

5

a. Firstrule:mostfollowers.Secondrule:largestpositionalweight.

AssemblyLineBalancingTable<CT=14>

WorkStation

Task

TaskTime

TimeRemaining

FeasibletasksRemaining

I

F

5

9

A,D,G

A

3

6

B,G

G

6

–

–

II

D

7

7

B,E

B

2

5

C

C

4

1

–

III

E

4

10

H

H

9

1

–

IV

I

5

9

–

b. Firstrule:Largestpositionalweight.

AssemblyLineBalancingTable<CT=14>

WorkStation

Task

TaskTime

TimeRemaining

FeasibletasksRemaining

I

F

5

9

A,D,G

D

7

2

–

II

G

6

8

A,E

A

3

5

B,E

B

2

3

–

III

C

4

10

E

E

4

6

–

IV

H

9

5

I

I

5

–

c.

a

b

d

c

f

e

g

h

4.

a. l.

2. MinimumCt=1.3minutes

Task

Followingtasks

a

4

b

3

c

3

d

2

e

3

f

2

g

1

h

0

WorkStation

Eligible

Assign

TimeRemaining

IdleTime

I

a

A

1.1

b,c,e,<tie>

B

0.7

C

0.4

E

0.3

0.3

II

d

D

0.0

0.0

III

f,g

F

0.5

G

0.2

0.2

IV

h

H

0.1

0.1

0.6

3.

4.

b. 1.

2. Assigna,b,c,d,andetostation1:2.3minutes[noidletime]

Assignf,g,andhtostation2:2.3minutes

3.

4.

7.

1

5

4

3

8

7

6

2

Chapter06-WorkDesignandMeasurement

3.

Element

PR

OT

NT

AFjob

ST

1

.90

.46

.414

1.15

.476

2

.85

1.505

1.280

1.15

1.472

3

1.10

.83

.913

1.15

1.050

4

1.00

1.16

1.160

1.15

1.334

Total4.332

8.

A=24+10+14=48minutesper4hours

9.

a.

Element

PR

OT

NT

A

ST

1

1.10

1.19

1.309

1.15

1.505

2

1.15

.83

.955

1.15

1.098

3

1.05

.56

.588

1.15

.676

b.

c. e=.01minutes

Chapter07-LocationPlanningandAnalysis

1.

Factor

Localbank

Steelmill

Foodwarehouse

Publicschool

1.

Convenienceforcustomers

H

L

M–H

M–H

2.

Attractivenessofbuilding

H

L

M

M–H

3.

Nearnesstorawmaterials

L

H

L

M

4.

Largeamountsofpower

L

H

L

L

5.

Pollutioncontrols

L

H

L

L

6.

Laborcostandavailability

L

M

L

L

7.

Transportationcosts

L

M–H

M–H

M

8.

Constructioncosts

M

H

M

M–H

Location<a>

Location<b>

4.

Factor

A

B

C

Weight

A

B

C

1.

BusinessServices

9

5

5

2/9

18/9

10/9

10/9

2.

CommunityServices

7

6

7

1/9

7/9

6/9

7/9

3.

RealEstateCost

3

8

7

1/9

3/9

8/9

7/9

4.

ConstructionCosts

5

6

5

2/9

10/9

12/9

10/9

5.

CostofLiving

4

7

8

1/9

4/9

7/9

8/9

6.

Taxes

5

5

5

1/9

5/9

5/9

4/9

7.

Transportation

6

7

8

1/9

6/9

7/9

8/9

Total

39

44

45

1.0

53/9

55/9

54/9

Eachfactorhasaweightof1/7.

a.

CompositeScores

39

44

45

7

7

7

BorCisthebestandAisleastdesirable.

b.

BusinessServicesandConstructionCostsbothhaveaweightof2/9;theotherfactorseachhaveaweightof1/9.

5x+2x+2x=1x=1/9

c.

CompositeScores

A

B

C

53/9

55/9

54/9

BisthebestfollowedbyCandthenA.

5.

Location

x

y

A

3

7

B

8

2

C

4

6

D

4

1

E

6

4

Totals

25

20

EQ\O<,x>

=

xi

=

25

=5.0

EQ\O<,y>

=

yi

=

20

=4.0

n

5

n

5

Hence,thecenterofgravityisat<5,4>andthereforetheoptimallocation.

Chapter08-ManagementofQuality

1.

Checksheet

WorkType

Frequency

LubeandOil

12

Brakes

7

Tires

6

Battery

4

Transmission

1

Total

30

12

7

6

4

1

Lube&Oil

Brakes

Tires

Battery

Trans.

Pareto

break lunch break

3

2

1

0

2

.

Therunchartsseemstoshowapatternoferrorspossiblylinkedtobreaktimesortheendoftheshift.Perhapsworkersarebecomingfatigued.Ifso,perhapstwo10minutebreaksinthemorningandagainintheafternooninsteadofone20minutebreakcouldreducesomeerrors.Also,errorsareoccurringduringthelastfewminutesbeforenoonandtheendoftheshift,andthoseperiodsshouldalsobegivenmanagement’sattention.

Poweroff

Person

Lamp

Missing

Didn’tturn

completelyon

Not

pluggedin

Outlet

defective

Defective

Burnedout

Loose

Lampfailstolight

Other

Cord

4

Chapter9-QualityControl

4.

Sample

Mean

Range

1

79.48

2.6

MeanChart:

EQ\O<=,X>

±A2

EQ\O<,R>

=79.96±0.58<1.87>

2

80.14

2.3

=79.96±1.08

3

80.14

1.2

UCL=81.04,LCL=78.88

4

79.60

1.7

RangeChart: UCL=D4

EQ\O<,R>

=2.11<1.87>=3.95

5

80.02

2.0

LCL=D3

EQ\O<,R>

=0<1.87>=0

6

80.38

1.4

[Bothchartssuggesttheprocessisincontrol:Neitherhasanypointsoutsidethelimits.]

6. n=200 ControlLimits=

Thus,UCLis.0234andLCLbecomes0.

Sincen=200,thefractionrepresentedbyeachdatapointishalftheamountshown.E.g.,1defective=.005,2defectives=.01,etc.

Sample10istoolarge.

7. Controllimits:

UCLis16.266,LCLbecomes0.

Allvaluesarewithinthelimits.

14.LetUSL=UpperSpecificationLimit,LSL=LowerSpecificationLimit,

=Processmean,=Processstandarddeviation

ForprocessH:

ForprocessK:

Assumingtheminimumacceptableis1.33,since1.0<1.33,theprocessisnotcapable.

ForprocessT:

Since1.33=1.33,theprocessiscapable.

Chapter10-AggregatePlanningandMasterScheduling

7.a. Nobacklogsareallowed

Period

Mar.

Apr.

May

Jun.

July

Aug.

Sep.

Total

Forecast

50

44

55

60

50

40

51

350

Output

Regular

40

40

40

40

40

40

40

280

Overtime

8

8

8

8

8

3

8

51

Subcontract

2

0

3

12

2

0

0

19

Output-Forecast

0

4

–4

0

0

3

–3

Inventory

Beginning

0

0

4

0

0

0

3

Ending

0

4

0

0

0

3

0

Average

0

2

2

0

0

1.5

1.5

7

Backlog

0

0

0

0

0

0

0

0

Costs:

Regular

3,200

3,200

3,200

3,200

3,200

3,200

3,200

22,400

Overtime

960

960

960

960

960

360

960

6,120

Subcontract

280

0

420

1,680

280

0

0

2,660

Inventory

0

20

20

0

0

15

15

70

Total

4,440

4,180

4,600

5,840

4,440

3,575

4,175

31,250

b. Levelstrategy

Period

Mar.

Apr.

May

Jun.

July

Aug.

Sep.

Total

Forecast

50

44

55

60

50

40

51

350

Output

Regular

40

40

40

40

40

40

40

280

Overtime

8

8

8

8

8

8

8

56

Subcontract

2

2

2

2

2

2

2

14

Output-Forecast

0

6

–5

–10

0

10

–1

Inventory

Beginning

0

0

6

1

0

0

1

Ending

0

6

1

0

0

1

0

Average

0

3

3.5

.5

0

.5

.5

8

Backlog

0

0

0

9

9

0

0

18

Costs:

Regular

3,200

3,200

3,200

3,200

3,200

3,200

3,200

22,400

Overtime

960

960

960

960

960

960

960

6,720

Subcontract

280

280

280

280

280

280

280

1,960

Inventory

30

35

5

0

5

5

80

Backlog

180

180

360

Total

4,440

4,470

4,475

4,625

4,620

4,445

4,445

31,520

8.

Period

1

2

3

4

5

6

Total

Forecast

160

150

160

180

170

140

960

Output

Regular

150

150

150

150

160

160

920

Overtime

10

10

0

10

10

10

50

Subcontract

0

0

10

10

0

0

20

Output-Forecast

0

10

0

–10

0

0

Inventory

Beginning

0

0

10

10

0

0

Ending

0

10

10

0

0

0

Average

0

5

10

5

0

0

20

Backlog

0

0

0

0

0

0

0

Costs:

Regular

7,500

7,500

7,500

7,500

8,000

8,000

46,000

Overtime

750

750

0

750

750

750

3,750

Subcontract

0

0

800

800

0

0

1,600

Inventory

20

40

20

80

Backlog

0

0

0

0

0

0

Total

8,250

8,270

8,340

9,070

9,050

8,750

51,430

Chapter11-MRPandERP

1.a.

F: 2

G: 1

H: 1

J: 2x2=4

L: 1x2=2

A: 1x4=4

D: 2x4=8

J: 1x2=2

D: 1x2=2

Totals:F=2;G=1;H=1;J=6;D=10;L=2;A=4

Stapler

TopAssembly

BaseAssembly

Cover

Spring

SlideAssembly

Base

StrikePad

RubberPad2

Slide

Spring

b.

4.

Master

Schedule

Day

Beg.Inv.

1

2

3

4

5

6

7

Quantity

100

150

200

Table

Beg.Inv.

1

2

3

4

5

6

7

Grossrequirements

100

150

200

Scheduledreceipts

Projectedonhand

Netrequirements

100

150

200

Planned-orderreceipts

100

150

200

Planned-orderreleases

100

150

200

WoodSections

Beg.Inv.

1

2

3

4

5

6

7

Grossrequirements

200

300

400

Scheduledreceipts

100

Projectedonhand

100

100

Netrequirements

100

300

400

Planned-orderreceipts

100

300

400

Planned-orderreleases

400

400

Braces

Beg.Inv.

1

2

3

4

5

6

7

Grossrequirements

300

450

600

Scheduledreceipts

Projectedonhand

60

60

60

60

Netrequirements

240

450

600

Planned-orderreceipts

240

450

600

Planned-orderreleases

240

450

600

Legs

Beg.Inv.

1

2

3

4

5

6

7

Grossrequirements

400

600

800

Scheduledreceipts

Projectedonhand

120

120

120

120

88

88

71

Netrequirements

280

600

800

Planned-orderreceipts

308

660

880

Planned-orderreleases

968

880

10.

Week

1

2

3

4

Material

40

80

60

70

Week

1

2

3

4

Laborhr.

160

320

240

280

Mach.hr.

120

240

180

210

a.Capacityutilization

Week

1

2

3

4

Labor

53.3%

106.7%

80%

93.3%

Machine

60%

120%

90%

105%

b. Capacityutilizationexceeds100%forbothlaborandmachineinweek2,andformachinealoneinweek4.

Productioncouldbeshiftedtoearlierorlaterweeksinwhichcapacityisunderutilized.Shiftingtoanearlierweekwouldresultinaddedcarryingcosts;shiftingtolaterweekswouldmeanbackordercosts.

Anotheroptionwouldbetoworkovertime.Laborcostwouldincreaseduetoovertimepremium,aprobabledecreaseinproductivity,andpossibleincreaseinaccidents.

Chapter12-InventoryManagement

2. Thefollowingtablecontainsfiguresonthemonthlyvolumeandunitcostsforarandomsampleof16itemsforalistof2,000inventoryitems.

Dollar

Item

UnitCost

Usage

Usage

Category

K34

10

200

2,000

C

K35

25

600

15,000

A

K36

36

150

5,400

B

M10

16

25

400

C

M20

20

80

1,600

C

Z45

80

250

16,000

A

F14

20

300

6,000

B

F95

30

800

24,000

A

F99

20

60

1,200

C

D45

10

550

5,500

B

D48

12

90

1,080

C

D52

15

110

1,650

C

D57

40

120

4,800

B

N08

30

40

1,200

C

P05

16

500

8,000

B

P09

10

30

300

C

a. Seetable.

b. Toallocatecontrolefforts.

c. Itmightbeimportantforsomereasonotherthandollarusage,suchascostofastockout,usagehighlycorrelatedtoanAitem,etc.

3. D=1,215bags/yr.

S=$10

H=$75

a.

b. Q/2=18/2=9bags

c.

d.

e. Assumingthatholdingcostperbagincreasesby$9/bag/year

Q=17bags

Increaseby[$1,428.71–$1,350]=$78.71

4. D=40/dayx260days/yr.=10,400packages

S=$60H=$30

a.

b.

c. Yes

d.

TC200=3,000+3,120=$6,120

6,120–6,118.82<only$1.18higherthanwithEOQ,so200isacceptable.>

7. H=$2/month

S=$55

D1=100/month<months1–6>

D2=150/month<months7–12>

a.

b. TheEOQmodelrequiresthis.

c. Discountof$10/orderisequivalenttoS–10=$45<revisedorderingcost>

1–6 TC74= $148.32

7–12 TC91= $181.66

10. p=50/ton/day

D=20tons/dayx200days/yr.=4,000tons/yr.

u=20tons/day

200days/yr.

S=$100

H=$5/tonperyr.

a.

b.

Averageistons[approx.3,098bags]

c. Runlength=

d. Runsperyear=

e. Q=258.2

TC=

TCorig. =$1,549.00

TCrev. =$774.50

Savingswouldbe $774.50

15.

Range

P

H

Q

D=4,900seats/yr.

0–999

$5.00

$2.00

495

H=.4P

1,000–3,999

4.95

1.98

497NF

S=$50

4,000–5,999

4.90

1.96

500NF

6,000+

4.85

1.94

503NF

CompareTC495withTCforalllowerpricebreaks:

TC495=

495

<$2>+

4,900

<$50>+$5.00<4,900>=$25,490

2

495

TC1,000=

1,000

<$1.98>+

4,900

<$50>+$4.95<4,900>=$25,490

2

1,000

TC4,000=

4,000

<$1.96>+

4,900

<$50>+$4.90<4,900>=$27,991

2

4,000

TC6,000=

6,000

<$1.94>+

4,900

<$50>+$4.85<4,900>=$29,626

2

6,000

495 497 500 503 1,000 4,000 6,000

Quantity

TC

Hence,onewouldbeindifferentbetween495or1,000units

22.

d =30gal./day

ROP =170gal.

LT =4days,

ss=Z

EQ\O<d>

LT=50gal

Risk =9% Z=1.34

Solving,

EQ\O<d>

LT=37.31

3% Z=1.88,ss=1.88x37.31=70.14gal.

Chapter13-JITandLeanOperations

1.

N =?

N=

DT<1+X>

D =80piecesperhour

C

T =75min.=1.25hr.

=

80<1.25><1.35>

=3

C =45

45

X =.35

4. Thesmallestdailyquantityevenlydivisibleintoallfourquantitiesis3.Therefore,usethreecycles.

Product

Dailyquantity

Unitspercycle

A

21

21/3=7

B

12

12/3=4

C

3

3/3=1

D

15

15/3=5

5.

a.Cycle1 2 3 4

A 6 6 5 5

B 3 3 3 3

C 1 1 1 1

D 4 4 5 5

E 2 2 2 2

b.Cycle1 2

A 11 11

B 6 6

C 2 2

D 8 8

E 4 4

c.4cycles=lowerinventory,moreflexibility

2cycles=fewerchangeovers

7. Netavailabletime=480–75=405.Takttime=405/300unitsperday=1.35minutes.

Chapter15-Scheduling

6.

a.

FCFS:A–B–C–D

SPT:D–C–B–A

EDD:C–B–D–A

CR:A–C–D–B

FCFS:

Jobtime

Flowtime

Duedate

Days

Job

<days>

<days>

<days>

tardy

A

14

14

20

0

B

10

24

16

8

C

7

31

15

16

D

6

37

17

20

37

106

44

SPT:

Jobtime

Flowtime

Duedate

Days

Job

<days>

<days>

<days>

tardy

D

6

6

17

0

C

7

13

15

0

B

10

23

16

7

A