CHAPTER 7Solution

1.

Week 1 2 3 4 5 6Leather 15 20 18 21 15 13Fabric 65 60 62 59 65 67

Sewing Assy0.55 0.45

Leather 1.2 0.66 0.54Fabric 1 0.55 0.45

Work CenterSewing 45.65 46.2 45.98 46.31 45.65 45.43Assembly 37.35 37.8 37.62 37.89 37.35 37.17

2.

Average labor hours:Sewing = 45.865 -- largest variance = .445 hoursAssembly= 37.53 -- largest variance = .36 hoursIt just does not look like a problem!

5.

Week 1 2 3 4MPS 20 30 35 20

WC 200Frame 34 49 56.5 34

WC 300Part A 23 33 38 23Part B 19 27 31 19Total 42 60 69 42

WC 400Part C 26 38 44 26

WC 500Part D 22 32 37 22

7-1

6.

a.Week 1 2 3MPS (bookcases) 35 50 40MPS (panels) 70 100 80MPS (shelves) 140 200 160

Machine Setup Run TimeEnd Panel Center Time Per UnitOperation 1 Saw 36 min. 5 min.Operation 2 Planer 18 min. 3 min.Operation 3 Router 48 min. 4 min.

ShelfOperation 1 Saw 30 min. 4 min.Operation 2 Molder 78 min. 5 min.Operation 3 Router 42 min. 5 min.Operation 4 Sander 6 min. 1 min.

WeekMachine center 1 2 3Saw 36+(35x5x2)=386 36+(50x5x2)=536 36+(40x5x2)=436

30+(35x4x4)=590 30+(50x4x4)=830 30+(40x4x4)=670Minutes 976 1366 1106Hours 16.3 22.77 18.43

PlanerMinutes 18+(35x3x2)=228 18+(50x3x2)=318 18+(40x3x2)=258Hours 3.8 5.3 4.3

Router48+(35x4x2)=328 48+(50x4x2)=448 48+(40x4x2)=36842+(35x5x4)=742 42+(50x5x4)=1042 42+(40x5x4)=842

Minutes 1070 1490 1210Hours 17.83 24.83 20.17

MolderMinutes 78+(35x5x4)=778 78+(50x5x4)=1078 78+(40x5x4)=878Hours 12.97 17.97 14.63

SanderMinutes 6+(35x1x4)=136 6+(50x1x4)=206 6+(40x1x4)=166Hours 2.27 3.43 2.77

7-2

b.Weekly Router Machine Load

Setup Run TotalWeek Hours Hours Hours MPSPast Due 1.5 16.83 17.831 1.5 23.33 24.83 352 1.5 18.67 20.17 503 40

c. Since the shelves must be processed at the sanding operation after routing they should be processed first at the router if the two parts arrived at the router on the same day. This way both parts would be in their final operation at the same time and the complete component sets would be available for assembly sooner.

7.

WeekWork Center 1 2 3 4 5 6100 5.33 6.17 6.17 6.17 6.17200 6.12 5.5 5.5 5.5300 13.25 9.5

Examples: WC 100, week 1 = 2 + (20x10/60)=5.33. WC 200, week 1 = 3+(30x5/60)+(15x5/2/60)= 6.12

8.

Week 1 2 3 4 5 6 7 8

Planned input 60 60 60 60 60 60 60 60

Actual input 68 70 75 70 68 60 55 55

Cumulative deviation 8 18 33 43 51 51 46 41

Planned output 65 65 65 65 65 65 65 65

Actual output 60 62 63 63 64 65 63 60

Cumulative deviation -5 -8 -10 -12 -13 -13 -15 -20

Actual backlog 50 58 66 78 85 89 84 76 71

7-3

9.

Product Line TotalWork Center A B C100 35 28 12 75200 25 37 56 118300 46 35 33 114

a.Work Center Worker

sMachines

100 2 2200 3 3300 3 3

b.Work Center Worker

sMachines

100 2 1200 3 2300 3 2

7-4