But you don’t need to split and close the job for the 8 to still show load. If there is a remaining qty, depending on how you have set up Epicor, the 8 will still be on the schedule.
I am close with these results. I setup a part with two detail parts. Top part is the G01, with P01, and P02 as the detail parts. I added sales order demand to match the customer’s request:
These are all firm releases, not make direct.
Based on this demand, I pretended that management created two top-level jobs to fulfill the demand.
The first job 999999/1 covers the first 42 pc of releases, and is set due to the earliest release date 4/9/26. The second job 999999/2 covers the last 54 pc of releases, and is set due to 7/2/26.
I have previously removed all stock for the top level part, and the detail parts. I also removed all other demand and jobs for these parts.
Now I run MRP for just the top level part. It suggests some jobs. Here looking at just the jobs related to the second top job, 999999/2. For 54 pc, it should suggest two jobs for the P01, and P02 parts. It does suggest the jobs, but the quantity is off by and extra 14 pcs. It should suggest the jobs at 54 pc each, instead of 68 pc each. That quantity of 14 is the amount of a single release. So MRP is combining something here, but I can’t tell why.
Here you can see the complete list of suggestions from MRP:
What can I show to help prove why the suggestion is +14 over the demand amount? What can I change to make sure the suggested amount matches the demand amount?
Note the job 999999/1 did create the correct suggestions for 42 pc for each detail job.
I am not sure why MRP is still suggesting top level jobs for U-000…1-5. The demand is set to not make direct. So I would think it would not try to create jobs for each release.
Ah! I forgot to set my top part to non-stock. Once I did that, MRP suggested exactly the right jobs (plus a bunch of extra stuff I have to ignore). I am concerned about setting that top part to non-stock, as we do sometimes need to stock the part if we make extra. How can I keep this top part as non-stock = false, but also have MRP suggest the correct quantities?
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I am floundering around quite a bit here… I realize I am not the man for the job. There are no others to do it, so I just keep trying.
Now that MRP suggested the jobs correctly, I see that they are all make to stock jobs. The top level jobs I created manually are MTS. I thought that setting the parts to non-stock = true, meant that MRP would make the parts to the job instead of to stock.
What does Time Phased Inquiry show for the top-level part with non-stock false (where you had the extra 14 pieces in suggestions)? That should help narrow down where MRP was coming up with that quantity and will show any make direct vs pull-from/ship-from stock discrepancies.
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And I’m glad that you have. I have gleaned some nuggets on this thread from @jkane, @tsmith, @cpilinko, and @Kovacs13. Thanks for asking!
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I went back and set top part to non-stock = false. Then reran MRP. Now it still suggests the correct amount:
I am so confused…
You will want to mark Lock Quantity on the manual jobs you created (99999/1 and /2) so that MRP does not try to reduce the job and replace it with the new U- suggestions. MRP is a just-in-time system and it sees that you’re making “too much” “too early” on those manual jobs, so it’s trying to reduce those jobs to meed the immediate need and then make new jobs for the subsequent releases.
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so going back to my RULES for MRP:
Never lie to MRP… or it will lie back:
- Order Dates and quantities should reflect what the customer wants/needs… not how you plan to make the parts
- Part Min/max/safety & Min/max order quatities and Order Multiples, and Days of supply should be set for the practicle limits for that part. ie… if you cannot make more than 100 at a time, then set the max order qty to 100. If you alway want to make 4 weeks worth at a time, set Days Of Supply to 48.
- Non-Stock should be used sparingly for those items that you will never plan to put into stock. If you anticipate overruns, or making more than you need for the first delivery, then you should make it a stocked item, allowing you to ship from stock.
- BOM and Routing need to be accurate
- Job Quantities should be accurate with correct start and stop dates.
- POs should have correct quantities and dates
- Stock levels need to be accurate
- Lead times need to be accurate
If you break the rules, MRP can only give inaccurate recommenations.
Once you see what it recommends, if you dont like it, then adjust. Most of the time these adjustments are done at the min order or order multiple, or days of supply.
Where I used to work, we made 99% of what we made “to order”… ie.. we didnt stock finshed goods (as a rule).. BUT… we also CHOSE to make ALL of our parts “To Stock”… This meant that if we had an overrun, we still had a place to put them. Then they could ship out on the next delivery. Example:
Sales order wanted 10 in week 1, 20 in week 2, 10 in week three. We could choose to make all 40 at once, or make them in three jobs. but because we had a high scrap rate (10-15%) that was not predictable. we often had a 1-5 piece overrun.. so we would tend to manufacture the first few jobs at higher than normal scrap rates, and lower as we got close to the end. We would ship our overruns at the end to finish out the entire order.
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I would like to not lie to MRP. Help me get there!
This would be fine if we could split the job at arbitrary quantities greater than a single release quantity.
We don’t have practical limits that we care about. I can see if we setup the top level demand correctly, then we could have MRP suggest those top level jobs. We are trying to wrest some control back from MRP by manually defining those top jobs, and letting MRP suggest the myriad of detail jobs that could be generated as a result.
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That really helped! After running MRP I have suggestions for just 4 jobs! 2 for each detail. Perfect! Now if only those jobs were make to job (to the main job) instead of make to stock.
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If you make extras, set the part to stock and set runout to true. Write a BPM that will set Stock and Runout parts to NonStock when quantity drops to 0.
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You said you don’t need to always split the jobs but sometimes you do.
When you split jobs would you have to make new top level jobs? just adjust the demand links as necessary.
If you have SO Line 1 Release 1 for 50 parts. And you have 1 job to make those 50, but you can only make 20. Then change the qty on that job to 20, and make a new job still to the same SO Line 1 Release 1 demand link for 30. The logic is the same for the multiple releases.
Your comment about not being the right man for the job is bullshit. MRP is complicated. Planning production is complicated. There are a lot of knobs to turn. You’ll figure it out. Start small, don’t get tunnel vision, and don’t turn too many knobs at once.
I suggested making your detail parts to stock so that if you do need to split the top level jobs it will make it a lot easier. If the MRP created sub jobs are direct to the top level job, and you need to split the top level job you’re going to be in a world of hurt.
If your SO Releases are unfirm you won’t get date or qty change suggestions for the top level jobs. It works well, you just need to be aware of the implications, which shouldn’t be too many since the top level jobs are manually created.
I see where you are going with this. We tried this approach once. If we have to split the detail job, then there is a good chance we will be splitting the top level job too. If we use demand links to the SO on the top job, we can reduce the quantity in a split, but we can’t split at quantities greater than the size of a single release. In this case the biggest release is 15 pc, so we wouldn’t be able to split the top job in quantities greater than 15.
Let’s say we need to ship 55 pcs, but release 1 is 50 pcs, and release 2 is 10 pcs. I can split off the 50 pc into a job and those costs carry over correctly. But I can only split and carry costs from a single release. Lets say I wanted to get those 5 extra pieces off of the main job, and onto the split with the other 50 pcs. I could move the demand manually from one job to the other, but any work done on those pieces is not transferred (along with the costs).
I really appreciate that, and all your advice!
There is some excellent information in this thread. I would also like to suggest you review your method of manufacture for every level feeding into the top level parts you are making.
- Pull As Assembly: assembly made within the parent job
- Plan As Assembly: assembly made in separate job
- None selected: assembly is consumed from inventory
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Just a reminder - Jobs cannot be moved in the schedule once any type of transaction is done on the job. if they want to reschedule the remaining quantity for accurate load against resources, a new job would be needed.
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With MRP suggesting jobs, can I define the job number for the jobs that I want to firm? I think this request comes from the way we always do things where we try to keep the job number the same across all detail parts.
For example, level 0 job 999999/1.
MRP suggests U-000000001, and U-000000002 to cover the make to job parts needed for the job. When I firm those jobs, I want to call them something like 999999/1-1, and 999999/1-2. Is this possible?
I know that I can change the Firm and Unfirm job prefix using Site Configuration. That is not quite what I wanted.
Not that we’ve found - aside from BPMs. Others in our org don’t care so I dropped the discussion - my OCD notwithstanding.
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Nope. My Idea for this expired. You should make a new one. I have always wanted that.
We have tried to work around it. I have not seen anyone succeed.
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Added a new idea: Allow Custom Firm Job Numbers | Epicor Ideas Portal
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