The basic process runs 3 shifts per day and it can be briefly depicted by following flow diagram
Optical Test-internal
Pro-Coat
Copper plate
Drilling
Optical Test- external
End of line test
Sizing
Machining
Lamination core
Treater procMess
Internal circuitize
Lamination composite
External circuitize
The targeted output for the plant is 3000 boards per day, five days a week, with plant running three shifts per day. But the plant has been failed to reach and maintain the targeted throughput at a steady rate due to manufacturing complexities associated with the product mix. It was also found that, the output of the pro-coat process is very slow (1200 boards/day) compared to the expected throughput and therefore Hal has to engage a vendor on the pro- coat process to fulfil the demand. This engagement of vendor has caused increase in cost per board and two days delay because of shipping up and back.
So the Hal is striving to increase the throughput of the pro-coat process and the purpose of this case study is to provide some guidance to them in their effort by giving some recommendations to improve the existing system.
Floor arrangement and the work flow of the pro-coat process
Daily demand = 3000 boards
Working hours = 24- (Breaks + Lunch + shift change + Meeting) = 24-(20X2X3+40X3+10X3+90/5) = 19.2 hrs
Demand = 3000/(19.2X60) = 2.604 boards/min
Assumption; 1. Demand = Arrival rate (ra=2.604 boards/min) 2. Arrival pattern exponentially distributed (Ca2=1) Machine Name | Mean process (load) time (min) | Std. Dev. Process Time (min) | Trip Time (conveyor) (min) | MTBF (hr) | MTTR (hr) | Setup time (min) | Availability |