15. Shown next is the MRP record for part no. 483. The current shop day is 100 (with 5-day weeks);

it’s now Monday of week 1. Open orders (scheduled receipts) are due Mondays (shop days 100, 105, 110, 115, etc.) of the week for which they’re scheduled. The shop floor has just reported that the batch of 40 on shop order number 32 has just finished at machine center A43 and is waiting to be moved to C06. It takes one day to move between machine centers (or to I02, the inventory location) and one day of queue time at the machine centers. (The inventory location doesn’t require the queue time, but one day of “machine time” is shown for clearing the paper work.) Part number 483’s routing and status are also given.

300 Chapter 8 Production Activity Control Problems 301 Week Part No. 483 1 2 3 4 5 6 Gross requirements 14 4 10 20 3 10 Scheduled receipts 40*

Projected available balance 20 6 42 32 12 9 39 Planned order releases 40 Q = 40; LT = 2; SS = 5.

*Shop order no. 32.

Part No. 483 Routing (machine center) A12 B17 A43 C06 I02 Machine time (days) 4 1 1 1 1 Status shop order 32 Done Done Done

a. Use a spreadsheet to replicate the MRP record and calculate the critical ratio for part no. 483.

Should the planner take any action?

b. What would the priorities be if the inventory were 23 instead of 20? What action should be taken now?

c. What if inventory were 17 instead of 20?