Question

A 10-station assembly machine has an ideal cycle time of 6 sec. The fraction defect rate at each station is 0.005 and a defect always jams the affected station. When a breakdown occurs, it takes 1.2 min, on average, for the system to be put back into operation. Determine (a) the hourly production rate for the assembly machine, (b) yield of good product (final assemblies containing no defective components), and (c) proportion uptime of the system.

Answer 1

Answer:

60/0.16 = 375 asbys/hr= Production rate

1.0 = yield

62.5%= Proportion Uptime

Explanation:

Tp = 0.1 + 10(1.0)(0.005)(1.2) = 0.16 min/asby.

(Production time (Tp) = cycle time+ no. of stations x probability of jamming the station x defect rate x breakdown time)

Rp = 60/0.16 = 375 asbys/hr= Production rate (Rp = 60/Tp)

If defects always jam the affected station,

then m = 1.0

Pap = (1 - 0.005 + 1x0.005) = 1.0 = yield

E = 0.1/0.16 = 0.625 = 62.5%= Proportion Uptime (cycle time/production time)