Chapter 9 1. The following table details the tasks required for Indiana-based Fr
ID: 377171 • Letter: C
Question
Chapter 9 1. The following table details the tasks required for Indiana-based Frank Pianki Industries to manufacture a fully portable industrial vacuum cleaner. The times in the table are in minutes. Demand forecasts indicate a need to operate with a cycle time of 11 minutes. Activity Activity Performance Time (mins) Predecessors Immediate Description Attach wheels to tub Attach motor to lid Attach battery pack Attach safety cutoff Attach filters Attach lid to tub Assemble attachments Function test Final inspection Packing 1.8 2.8 3.8 A, E 3.2 3.7 D, F, G a) Balance this line using the LPT heuristic. b) Calculate the theoretical minimum number of workstations required. S t | 's-2.8 c) Calculate the efficiency of your line from part a r 3 g+2 + 5, 2 + 3. T+2+2 29,3 29.3 : 2.1Explanation / Answer
Task Time Pre ES EF A 5 None 0 5 B 1.8 None 0 1.8 C 2.8 A 5 7.8 D 3.8 A,B 5 8.8 E 3 B 1.8 4.8 F 2 C 7.8 9.8 G 3.2 F 9.8 13 H 3.7 D,E 8.8 12.5 I 2 H 12.5 14.5 J 2 E 4.8 6.8 Total cycle time 29.3 Ans A Task Time Work station Time remaining with WS A 5 A 6 D 3.8 A 2.2 H 3.7 B 7.3 G 3.2 B 4.1 E 3 B 1.1 Spare C 2.8 C 8.2 F 2 A 0.2 Spare I 2 C 6.2 J 2 C 4.2 B 1.8 C 2.4 Spare TCT Total cycle time 29.3 TC Target cycle time 11 (TCT/TC) Min Workstation 2.663636 3 Ans B Idle time 3.7 TCT/(5*11) Efficiency of general cycle 53.27% Task Time Work station Time remaining with WS A 5 A 6 D 3.8 A 2.2 H 3.7 B 7.3 G 3.2 B 4.1 E 3 B 1.1 Spare C 2.8 C 8.2 F 2 A 0.2 Spare I 2 C 6.2 J 2 C 4.2 B 1.8 C 2.4 Spare Efficiency 88.79% 29.3/(3*11) Ans C If cycle time were 10.8, as the common spare can be reduced Efficiency 90.43% 29.3/(10.8*3)