MRP only suggests material

Hello everyone,

My company is seriously considering whether to run an MRP. If the MRP process can be operated as it is, of course, it will bring good results to the company(Inventory reduction, delivery time, etc.) Unfortunately, each company has its own business process, so there will be some parts where it is difficult to operate the MRP process as it is.
Epicor’s MRP process I sketched out is as follows. But I have one question.
MRP proposes Job and PO. Can’t MRP only offer PO?
So we did not generate the MRP process, only Generate Purchasing Suggestions. However, the problem with doing so is that it does not take into account FG’s stock, but only considers the quantity of Jobs. In other words, if you need 100 FGs and you have 60 FGs in stock, I would like to suggest the quantity of RMs required to make 40 FGs. This is the basic logic of MRP. However, my company wants to manually put the job separately. The reasons are too many such as that the forecast is not accurate, that the job is directly outsourced, and so on.
So, I am wondering if it is possible to set the MRP so that it proposes the quantity of RM considering the FG stock quantity but does not create a job.

I dont believe so as this would potentially be like trying to find a needle in a hay stack if you were trying to find what created it

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MRP for Jobs and Generate Purchase suggestions are two separate processes. MRP is for manufactured parts and Generate Purchase suggestions are for purchased parts.
We use only Generate purchase suggestions and it works great. And it does take existing stocks into account. Everything depends on the min/max stock and order multiples, lead times settings etc for the part.

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Yeah, as @Vinaykamboj says, you guys can just use the Generate PO Suggestions side of MRP it’s on the menu.

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I wonder about this. We tested in the pilot that only Generate PO Suggestions run without running the MRP Process. But there was one problem. When only Generate PO Suggestions was performed, Required Qty was brought as FG Part of Job, but FG’s On hand Qty was not taken into account.
For example, if the number of jobs (FG) is 100 and the on-hand of the FG is 60, the RM’s purchase proposal should only be 40, but 100 were offered as it is, just like the number of jobs.

Hi @pilio.lee. I have to go with what @Vinaykamboj said in that Gen PO sugg does taken into both current OH stock and also inbound POs. PO Sugg does take many part parameters but we’re seeing it behave as expected.


The Purchase demand for RM ( raw materials ? ) Should be for 100, its satisfying the demand for 100 of the FG for 100. Lets say in the BOM for the FG ( FG1) it call for 1 each if a raw Material ( RM1) . You have 25 of RM1 on hand. You should get a demand to purchase 75 RM1 .

If you want to only build 100 of FG1, you will have to implement a forecast for 100 FG1 and run MRP to create the demand for the jobs which in turn creates demand for the RM parts.

In your given case, there will be an MRP Suggestion to reduce the job of 100 to 60 provided you have a forecast and have run MRP.

I hope this helps.


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Is your FG part marked as Non-Stock? If so, then existing inventory will not be considered.

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Having MRP create jobs is to drive the materials is what it does.
MRP does not force, or require you to firm up the jobs.
When jobs are created, they will adjust what unfirm jobs are created, as will the FGs that are produced and placed in stock.

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To help you understand, I think I need to explain more about my company business process. If I operate Epicor’s basic MRP Process, my concerns are resolved. But, there is an issue where Epicor’s basic MRP process cannot be utilized.
Because even with the same FG, the job materials are constantly changing. Even the same FG sometimes has raw materials of A, B, C, and D, and sometimes has raw materials of B, D. Therefore, the raw material of the BOM cannot be used as it is.(Of course, there should be a standardized BOM, but the problem is that there are too many cases. Discussing this gives me a headache.)
Running the MRP process will make a PO suggestions with the material and quantity of the BOM. But, since the raw materials and quantity required by the job are different, my purchasing department may purchase the wrong one. So, I did not run the MRP Process to make PO suggestions with Job Materials that have already been deleted (or added) from the job entry, but only Generate PO Suggestions.
However, the problem with doing this is that the job creator has to create a job taking into account the current stock of the FG.
Running the MRP Process will deduct FG’s inventory from the quantity of Forecast/MPS, but unfortunately we can’t use it.

Nothing new to say, but I’ll repeat the others’ thoughts.

MRP is for jobs. If you don’t like the jobs it makes, that’s perfectly respectable. Don’t use it.

MRP does create PO suggestions at the end, after making the jobs.

But “Generate PO suggestions” makes PO suggestions with no jobs.

Do you want MRP to make some jobs but not others? For example, MRP should not touch finished goods? Then mark those parts as “Process MRP = false” in the PartPlant (sites tab of Part Entry). Also I would think you also want to mark it as “Generate PO Suggestions = false.”

It’s really, really normal to be really finicky about your finished goods jobs and helicopter-parent those every day. Those are the core and you have to baby them. Then use the system to do the rest.


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From you description sounds like you have SO demand for assemblies

  • which in turn would need jobs at some point… but don’t want just yet
  • and the jobs would then require your materials/purchased parts?
    i.e. you can’t get directly to purchased part suggestions because the jobs won’t yet exist?

Just curious… if you have run the Time Phased Materials Requirements report?

  • if any Part Qtys shown there would be useful?
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So even if you could get MRP to run material PO’s only, How would it know what to purchase? Unless you tell it what the flavor or the month is for the BOM, (which you would do by creating the job) how is it possible for MRP (or anyone for that matter) to know?

It sounds to me like you have some chicken or the egg circular reasoning going on. You are trying to plan jobs based on what you have in stock, and at the same time trying to decide what to buy based on the jobs that you have planned.

You ultimately have to pick one or the other to be the master. You either need to set a minimum on hand quantity and just buy to that, (which means higher inventory level) then make the jobs according to what you have in stock. Or you need to decide what you need on the jobs and buy to that, and stop looking at what you have in inventory to decide how you are going to buy for the jobs.


Looking back on this issue, it seems I was looking for a futile solution.
It’s a problem with my company’s business process, and if I try to solve it with a system, I think I’ll have to find another way. Thank you for your attention.


You are right. It is a problem with my company’s business process that cannot execute purchases according to the BOM. I can’t even plan if I can’t execute according to the BOM. I was wrong about trying to solve this problem at Epicor. Think of it as a complaint about my company’s business process. I’ll consider another option. thank you.

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It sounds like you have sales orders for parts that are marked as Make Direct. If you have a make direct item, then MRP ignores the FG Qty… Example:

  1. you have 100 FG in stock
  2. you have a new sales order for 25 FG
  3. IF the item is marked as a STOCK item, then MRP will NOT make a job, but will assume you can use 25 from stock
  4. IF the item is marked as NON-STOCK, then MRP WILL create a JOB.

Another thing you mention is that you don’t make your jobs from the BOM but modify them. BUT it sounds like you might be making wrong assumptions. If you make the job, you can change the BOM in the Job Material list. If you do this, once you schedule the job then MRP will make suggestions to purchase the material IF you need it.

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Assume neither FG nor RM are in stock. My company’s FG is a stock item.
If I run MRP in Forecast/MPS/SO input situation, a job to make the FG will be created.
And if there are raw materials A, B, C, D in the BOM of that FG, it will propose A, B, C, D to PO. However, the raw materials required in the job change every time. The purchasing department will already purchase A, B, C, and D. We can modify the Job Materials as soon as a job is created in MRP, but that is not possible.