Hi, guys,

We have items that may be produced from its raw material or from its semi finished good. To make matters worse, the item has multiple step production process and the purchased semi finished good may be semi finished good from any step of the production process. In other words, sometimes we buy the semi finished good of 1st operation, sometimes of 2nd operation, sometimes of 3rd operation, and so on, and then perform production internally only for the remaining steps.

We have come across several alternative models for this, but none is satisfactory so far:
Create non phantom item for every single semi finished good in multi level routing of the finished good. This way we can easily buy semi finished good from any production step. But then, creating a new FG data is a pain considering the number of semi finished good to be created per FG. Also, to produce a FG, multiple Production Order numbers will be involved. And for every production step we'll have to do outbound and inbound of goods
Same as above but use backflushing for the semi finished goods. This eliminates the need to perform outbound movement of goods, but then we'll have to perform stock adjustment often to account for the difference between actual material issue and backflushed issue
Having single level BOM will make it hard for us to buy the semi finished good
We can set up a single level alternative dummy BOM using different effective date. The alternative BOM will contain a dummy semi finished good with one dummy operation. We then can buy the dummy semi finished good. But then, we have to modify the operation sequence in production planning every time we'd like to use the semi finished good to make finished good. Not to mention it'd be hard for MRP to identify which BOM to use based on whether the raw material or the semi finished good is available
Any other alternative model, guys? Thanks very much for any input. Happy new year

Rgds,
Paul

Hi Paul,

What triggers the decision to make-or-buy?
If the planner decides it's better to buy a (semi)-product, he simply cancels the planned MRP-production order and creates a purchase order........
Running a net-change MRP should 'reset' all material demands for the just canceled prod.order.

No BOM structure (with or without phantoms, single or multi level) will help when you don't have a 'logical' way of making the make/buy-decision

So I don't think this can be handled by (standard)software. (as soon as you can think of an algoritm that describes your make/buy-decision, you can try 'temporarily switching' the itemtype from purchase to manufactured and vice versa; minor customisation)

(In B50c you can use sourcing rules.....so for an item you can define that X% is manufactured and/or Y% is purchased.....seems an answer, but the ratio is fixed, so we're back at the question what triggers the make/buy- decision)

Dear just_fro,

You just confirmed my fear that this situation can't be modeled easily. The client decides to be too flexible and allows purchasing the semi finished good from any stage of the production process. Let me think of other alternative then

Rgds,
Paul