Answer:
In the PC board assembly operation, assembling electronic components into printed circuit boards. As operators work on batches of 45 printed circuit boards. Each board requires 5 minutes of board assembly time.
Total time required = 5 min (value added)
moves the assembled boards to the final assembly area. This move takes 10 minutes to complete.
Total time required = 10 minutes (non value added – move time)
The final assembly for each stereo unit requires 15 minutes and is also done in batches of 45 units.
Total time required = 15 minutes (value added)
A batch of 45 stereos is moved into the test building, which is across the street. The move takes 20 minutes.
Time required = 20 minutes (non value added – move time)
Before conducting the test, the test equipment must be set up for the particular stereo model. The test setup requires 25 minutes.
Time required = 25 minutes (non value added – wait time)
In the final test, the 45-unit batch is tested one at a time. Each test requires 9 minutes.
Total time required = 9 minutes (value added)
shipping for packaging and final shipment to customers. A complete batch of 45 units is sent from testing to shipping. There is no move time between these two operations
Time required = 0 minutes
Packaging and labeling requires 10 minutes per unit.
Total time required = 10 minutes (value added)
Formula for Within-Batch Wait Time = (Total Time to Perform Operations) x (Batch Size – 1)
Calculation -
Value-added time required
PC board assembly =5 minutes
final assembly= 15 minutes
Testing = 9 minutes
Shipping = 10 minutes
Total Value-added time = 39 minutes
Non-value-added minutes:
Wait time (within – batch wait time) -
Wait time at PC board assembly = (45-1) *5 = 220 minutes
Wait time at final assembly= (45-1) *15 = 660 minutes
Wait time at Testing = (45-1) *9 = 396 minutes
Wait time at Shipping = (45 -1) *10 = 440 minutes
Total wait time within batch = 1,716 minutes
Set-up time = 25 minutes
Total wait time = 1,741 minutes
Move time minutes -
From assembled boards to the final assembly area = 10 minutes
From final assembly to test building = 20 minutes
Total Move time = 30 minutes
Total non-value-added time = wait time + move time = 1,741 + 30 = 1,771 min
Total lead time = value added + non value added = 39 min + 1771 min = 1,810 min
Value-added ratio (as a percent): Value added time / Total Lead time
= 39 / 1810 = 2.2%
