Alternate items in formulas in AX 2012

A 2x ex-colleague, Steve Bradford, (I’ve worked with him in two separate companies) posted a query to the Microsoft Dynamics AX community forum here.

He’d got an odd result when he setup the Alternate item functionality. Here how it goes. In a Formula create a ‘Plan group’. The primary item in the plan group gets a BOM line quantity, and a priority of 1. Alternate items get assigned to the same Plan group with a quantity of zero – and they’ll be processed in Priority sequence. Here I’ve just got two normal components (TS-A and TS-B), and one pair of Alternate items (TS-SUB1 and TS-SUB2)

Next I post an inventory journal so that I’ve plenty on-hand for TS-A and TS-B and TS-SUB2, and a limited quantity of TS-SUB1 (the primary item in the Plan group).

Next I’ll setup a monthly forecast for my formula item. I’ve got enough stock of TS-SUB1 for the first month’s forecast, but not enough for later months. I generate some planned production orders by opening the item’s Net requirements and updating master planning for this item. Looking at the ‘Derived requirements’ for my first planned batch order I see that the demand, as expected, uses up my stock of TS-SUB1:

And the next planned order uses the alternate item:

OOPS – that was a surprise!

However, thinking about it, the processing that is required here relates to the fact that the system’s not going to create a planned supply for this item, but instead, if the alternate item is available, the alternate item is going to be used as the supply – so really we need to run a full regenerative master plan across all items (or at the very least plan the formula item and it’s components).

After master scheduling has been run across all items I see:

That’s better!

There’s a common requirement for this scenario – where an item is being replaced by a new item (or version), but where you want to use up the existing stock before starting to use the new item. Fairly typical in packaging. Master planning handles this run-out / cut-over scenario well, but unfortunately this functionality is only available to Formula items – it’s not available to traditional BOM items, which is a shame, because I’ve come across this scenario in those discrete manufacturing environments more often than in the Batch order processes using Formulas – where the formula cut-over is often more tightly controlled.

Although master planning handles the Alternate items well, the production order falls short. Using the same on-hand scenario as above (only 100 of TS-SUB1 available) I’ve created a batch production order for 200, and estimated it – all of the demand is assigned to TSSUB1 even though I don’t have enough of that item and I have an alternate item available.

When I start the production order, the alternate item will only be shown on the picking list if I tick the ‘Complete picking list journal’ check-box (remember that the alternate items have a zero BOM line quantity):

There’s nothing on the Picking list journal to indicate the alternate item and how it relates to its Plan group:

And nothing on the standard Production picking list journal report either:

The link between the Alternate items (the Plan group) isn’t shown on the Max. report as finished inquiry either, although it would be a minor customisation to include that information:

So some hits, some misses – this functionality can be useful but probably needs minor customisations if it’s going to be widely used.