Planning Alt Methods

Our company is implementing MRP to manage jobs and material procurement. Currently, MRP creates jobs, but we immediately firm them, essentially locking them in. This creates released jobs waiting for production, even for orders 12-15 months out, especially when orders have staggered delivery dates.

There’s a reason for firming jobs early, but it’s causing problems, particularly with scheduling. Here’s the issue: When an order arrives, procurement places material orders based on the job. Ideally, materials would be delivered in line with order releases. However, parts might be unavailable, or limited quantities are only obtainable before needing a similar, but different, material.

This different material might require other changes within the job to achieve the same outcome. Importantly, the final product remains the same, only the manufacturing method changes (no impact on top-level part or revision). This is where alternate methods in MRP would be ideal.

Currently, we can only modify a job after firming it, usually done manually for simple part swaps. Alternatively, we can reload the job with the alternate method. Both achieve showing the correct purchasing needs. However, our challenge is:

  • Can jobs remain un-firmed while allowing alternate methods to be selected at the sales order level? This ensures procurement requests the right parts.
  • If we leave suggestions unfirm, the system only recommends the base version, never suggesting the alternate part purchase. Conversely, using the alternate method wouldn’t suggest using remaining stock of the original part.

We’re looking for any suggestions to address this situation, or other methods to achieve a similar outcome. Thanks in advance.

Alt methods are a multi-site thing. It lets you define site-specific resources for each manufacturing plant. While you can use it to define multiple ways to build a part in a single site, that’s not what it’s meant to do. As such (as you’ve noticed), the system will not help you manage your capacity in this way. You’re supposed to set one “primary” method per site and that is what the system will use for MRP.

The system will let you define substitutable materials (e.g. if we’re out of 4x6 plywood, you can cut down a 4x8). It doesn’t really let you flex the MOM based on the BOM though.

Can you break this into a multi-level assembly kind of thing? E.g. Final Part X needs Mtl A. Mtl A is out of stock, but Mtl B is suitable but needs processing. Create a MOM for part A that takes B as input and turns it into A?

Thanks for the response. So would a new revision be more appropriate?

MRP will only ever use the newest approved revision (by effective date).

I added another suggestion as an edit to my last post: break out the material change into its own job or subassembly.

Unfortunatley the material we are referencing is PCB parts with a lower or higher tolerance and not something that the user can modify, like a sheet of wood to a smaller size.

When using substitue materials, this is where we are going into the firmed job and manually removing the out of stock part and adding a new part. Is there a better way for alt or substitue parts to be processed?

I’ll put an asterisk on this… there is a checkbox on the Part Master called “Use Part Rev”. This checkbox is selected by default, but if you unselect it on a NonStock part then the SALES ORDER (so it’s MTO only) can select any approved revision that will flow through to MRP.