LAM

OM-II SECTION 'B & D' 2003 PRE-MIDTERM ASSIGNMENT


A. Swoosh Inc. Line Design using Simulation [10 marks]

Swoosh Inc. has a 3 stage production line for its brand of sneakers. The first machine cuts the material, the second forms it into shape, and the third machine performs the sewing and gluing operations. There is a storage "buffer" between the stages to "uncouple" the processes. Each storage buffer has the capacity to store 4 sneakers.

Stage 1 has an average Processing Time of 2 minutes (standard deviation 0.5 minutes), during which it produces material for 4 sneakers. Stage 2 operates on one unit at a time, requiring 25.5 seconds per unit. After each hour of use, stage 2 must be stopped and cleaned, which requires 10 minutes. Stage 3 has a cycle time that averages 28.5 seconds with almost no variation, but 10% of the units must be scrapped.

(a) How many sneakers per hour may be produced, on average?
(b) What happens if storag...