MRP Suggestions and Exceptions on Time Phase


(Joe Simmons) #1

I can not reconcile the results in E9 MRP Time phase. on most parts I look at. 1 example: Purchased Part “A”

1)The balance on hand nets against Released and engineered (all with past due start dates) jobs as expected

  1. The first receipt record for a PO occurs in current week, the qty on the PO far exceeds any Order Policy modifier or code in the system, PO Lock QTY / Date on the PO are not selected, and stock on hand prior to projected receipt was far in excess of the Safety Stock value…No message or exception is posted.

  2. Multiple jobs peg against this new balance for several weeks, the projected balance falls bellow Safety Stock 3 weeks out and an exception is flagged on Time Phase. “Below Safety”

  3. Inventory continues to net against multiple jobs for several more weeks with “Below Safety” exception posted each day.

  4. Finally a PO Posts and On Hand now exceeds Safety Stock…Time Phase Suggests that I Reduce the PO by a qty that puts me below the safety stock!!! and then throws a “Below Safety” on the suggestion record!!!

  5. Six days after that it Suggests a New PO for 1,000 more parts than the PO line it previously told me to reduce

Can anyone help me explain this. I have been working with MRPs for 25 years and I cant figure this out.

(Bruce Ordway) #2

As for the reduce suggestion…
I’ve seen suggestions I consider “odd” for parts where Min/Max/Safety qtys have been specified.
As far as I can tell, this is “by design” the system create reduce/cancel suggestions because these not “direct” demands for a sales order or job. i.e. how it reacts to “artificial” demands.

Do you already have a test system setup?
If so, it might be interesting to experiment there

  • remove the safety stock qty?
  • and/or play around with reschedule in/out deltas if you haven’t already.