Should we run Generate PO Suggestions as Regenerative each night? If no, why not?

(Utah Taylor) #1

Hello All,

We had a strange issue today where a suggestion wasn’t being suggested for materials in jobs that should have generated a suggestion. And yes, the parts are set up correctly. We took a backup of our live environment and restored it to our test environment and even there, we were not getting a suggestion, even after running generate suggestions-Net Change. I then ran the Generate Suggestions as regenerative and like magic, the suggestions appeared.

In short, is there any reason we shouldn’t run generate suggestions as regenerative each night?

Thanks in advance for your help.



(Tim Shoemaker) #2

This is an “It Depends” answer…

  1. many companies run full regen every night… no problems
  2. some companies run full regen every weekend, and then net change daily
  3. some companies only run net change with no problems

BUT… there are some weird conditions in (variance due to complex BOM structures) where net Change will NOT work, or even takes longer than full regen.
ALSO… if you only run net change, you can get to a condition where nothing “changed” recently for a part, but it SHOULD still get net change run for it… this happens if a demand is created… net change ran, but the date is outside the planning window. Net change will ignore it the first time, and then never replan it because it never “Changes”. For THIS reason, we also have a program called “MRP Recalc Needed” which should be run regularly if you always run Net Change. This will trigger the Net Change flags for conditions where the planning window caused it to be ignored.

All that said… my personal preference would be to simply run full regen on a daily basis.

(Utah Taylor) #3

I am wondering if that is what happened. But in order for demand to be created, the job has to be released right?

(Ernie Lowell) #4

To Epicor, the “demand” is the sales order OR inventory usage (bringing onhand quantity below min) OR a forecast OR MPS (or whatever else)… the job itself is the “supply” to meet the demand. If the job is already released and it satisfies the demand, then there will be no suggestion.

(Utah Taylor) #5

What I meant to convey is that the job is demanding the purchased material- the material that is not showing up in the suggestions. So when does MRP see the demand for the material, when the job is released, correct?

(Ernie Lowell) #6

No, it gets seen when the job is created, whether it is firm or released or not. If you look in Time Phase you can see unfirm jobs and unreleased jobs.

(Rick Stannard) #7

MRP will see the demand as long as the job is engineered. It does not need to be released.

(Tim Shoemaker) #8

There are two exceptions.
Jobs just be FIRMED for
1: purchase direct parts
2: subcontract operations.
OTHERWISE all other purchased items on an unfirm job will be planned and suggested my bro no matter howbit is run.

(Utah Taylor) #9

So what @DavisStd1 is saying is not exactly true? Unless you can’t engineer a job until it is firmed. Then what he said is technically true.

(Tim Shoemaker) #10

MRP will create unfirm engineered jobs (you cannot create an unfirm job manually). My normal recommendation is to leave a job unfirm as long as possible (till the day before you start) so that IF there are any changes (sales order qty, sales order date, BOM changes, routing changes, inventory adjustments, etc) MRP can automatically adjust the job to accomodate. BUT once you firm the job, you are essentially telling MRP “This is what we will be doing” and from that point on, you will only get SUGGESTIONS to reschedule and/or change quantity, but it wont do it for you… also if the bom changes, it will NOT suggest to fix those in any firm job.
BACK TO THE QUESTION: the ONLY time i recommend that a job get firmed early is:

  1. if you have additional (custom?) engineering to do in the job - you cannot change an unfirm job.
  2. you have a purchase direct part, and it is within the lead-time of that part, and you need to cut the PO.
  3. Typically, you dont need to cut a po early for outside processing, but there could be a case where you need to have a PO ahead of releasing to “warn” your supplier that it is coming. If that is the case, then you would need to firm it to get the suggestions.

(MIGUEL S.) #11

We are still currently in E9 702A and we run a full Regen for that exact reason. We created a demand (sales Order) and we never got the job created. When I looked at the MRP logs, the PN was processed but never saw the Order. So I looked at the PartDtl table and the demand was there.

I never really rec’d an answer from Support, so I just ran Regen. Regen for us takes 1.5 hours, so it was not a huge deal, but never getting a suggestion was.

@utaylor what version are you on? We are almost going live on 10.1.600.22 and havent seen that issue. Then again it was just random.

(Utah Taylor) #12

We are on 10.1.500.35 and I haven’t had anyone bring me this issue before.Maybe it’s because we do @timshuwy 's method of Full regen on weekends, net change daily and the timing was just right that the regen took care of any problems and the planning window worked out every time where waiting the whole week before seeing the suggestion didn’t bite us. In this case it would have caused problems because the day out buyer noticed this error was the day that the PO needed to go out. We are going to see how long full regen takes in out live environment. It took 24 minutes with 1 processor in our test environment, but that environment runs on slower disks so it should be even faster in our live environment.

Thanks for your feedback Miguel.

(Tim Shoemaker) #13

You can also run it on 2-3 processors and it should run really fast then.

(Utah Taylor) #14

That is the plan! Thanks again @timshuwy