Why is master scheduling generating planned works orders for phantom BOMs much earlier than the planned date of the parent item

Finance and Operations/AX User Forum
1

We are installing AX 2009, and have encountered the following issue:

All of our in house production items are made up of at least 1 phantom BOM (as we do not stock these) and a possible subassembly BOM, plus addiional BOM lines. we have found that the parent BOM item can have a big difference between the order date (when the production can be started) and the delivery date ( the date the production can be completed). This is not only driven by capacity reservation, but the the different times that master scheduling believe the phantom and subassembly BOMs can be produced.

For example: product A is made up of phantom BOM 1 & 2, as well as 6 other BOM items. There is a demand on product A which needs to be fulfilled within 2 weeks.

master scheduling is run and phantom BOM 1 can be made in 14 days as all materials are in stock, except 1 which has a lead-time of 7 days, with an issue margin of 7 days.

Phantom BOM 2 cannot be made for 60 days due to the leadtime of a component material.

The parent BOM therefore has a order date of the today plus 14days, and a delivery date of today plus 60 days.

We would only firm the planned works order for the parent item when we were able to make all the product, i.e. today plus 60 days. we would not make and stock the phantom item BOM 1.

However the planned purchase orders that are generated are telling us to order the missing materials from phantom BOM 1 today in order to make in 14 days as per the original requested date of the parent item. there is no action message to postpone this purchase order.

this would cause us to commit to material stock which was not required.

Is this correct AX behaviour? Is there a parameter/ process that I am missing?

Any advise gratefully received

2

I would probably need a clearer example because I am not getting this in my head (sorry), but my first question is are you using future messages to push out the 60 days and do you update the requirement dates to reflect the future dates?

3

Thanks for response Adam. Yes we are using futures messages to push out the planned works order to the longest material lead-time. And yes we are updating the requirement dates to reflect the futures date.

Below is another example:

Parent product: 376271 has a planned works order with order date of 30-11, and delivery date of 14.01 (the requested date is 29-10, so PWO has a futures message)

This product is made up from 2 phantom subassemblies (BOM1 & BOM2), and one other BOM item (ITEM C)

BOM1 has 2 BOM item (ITEM A and B)

BOM2 is also comprised of ITEM A and B (but in different quantities)

Item A has leadtime of 84 days, there is stock on hand to fulfil the production of BOM1, but not for BOM2

item B has leadtime of 9 days, there is no stock

item C has leadtime of 42 days, there is no stock.

Therefore a planned purchase order is generated to order item B and C for BOM1. item B PPO has a delivery date of 29-10, but an action message to postpone to 30-11. The PPO for item C with delivery date of 30-11. BOM1 can theortetically be made on 30-11 (however a planned works order is not generated as this is a phantom BOM, not a production BOM) We would not want to produce any element of the parent item until all component parts could be produced and the item completed.(14.01)

BOM2 cannot be produced until 11.01 due to the long leadtime of ITEM A. A PPO for ITEM A is generated for delivery on 11.01, therfore enabling the parent item to be completed by 14.01.

In the above example we do not want to place any purchase orders for the phantom or any subassembly component, that can be made earlier than the parent product.

Is there anyway that the phantom items cannot hang off the final date of the parent item.

In the above example we would order item B weeks before it is required, and the on hand stock we have of ITEM A would be incorrectly tied to making BOM1 as it would never be made on that date), when in reality it could be used for other production where the parent code can be completed sooner than 14-01.

Can anyone please help with confirming whether this logic is correct? Or advise whether there are any settings that need to be altered to get the correct results.Thank you.

4

On the master plan what are your settings for the Action message “Use Postponed Date as Requirement Date” and the Future Message “Use Futures Date as Requirement Date”?

Your lead time for the parent on the route is presumably 3 days driving the 11.01 statement for BOM2 and this should cascade as the purchase requirement date of the phantom items.

5

Thanks for response. For the future message we use ‘futures date as requirement date’ but do not use the setting ‘use postpone date as requirement date’ for the action message.

The BOM2 phantom starts on the 11.01 and completes on 14.01 (12.01 &13.01 is weekend with no capacity). This is driven by the route.

Is there no way of forcing the purchase of the phantom items to take the futures date of the parent?

6

Can you tell me why you are not using the “use postpone date as requirement date”? The issue will be your top level BOM is being pushed out with a futures date, but the phantom is using the original requirement date to plan against causing you the issue you are experiencing. If you ticked this then it should cascade through correctly so the sub-production is in-line with the parent. Planning pegs the phantom with a “Dynamic Order” to plan from and it is getting the dates here from teh original requirement and not the futures date because it is what you have said you want it to do.

Can you set this flag to true and run it agains to confirm it does what you want it to do?

7

Thanks Adam

I have tried this and there does seem to be a marked improvement in the results I am seeing. I am still analysing the results but as yet have not found an example where a phantom is being produced earlier than the parent. Regarding why we have not used this tick box before… I did not think this would effect the phantom orders as this field: master planning> set up>master plans> action tab ‘update postponed date to requirement date’ refers to planned purchase orders not planned dynamic orders.Can you explain a bit more about what this feild actual does, and if you have this ticked how this works in conjuction with the action tab settings in individual coverage groups. As our current set up we do not have the action message ticked for the subassemblies (phantoms and production) which are under coverage group WIP. Does this need to be ticked?

One other question (sorry): within out parent BOMS we have BOM items (which hang off the parent date) we have phantom BOM (which with this new setting seem to now take the requirement date of the parent) and in some parent BOMs we also have a subassembly production BOM (*pkp). These *PKP production BOMs still appear to take their requirement date from the parents original date, albeit they do have an action message to postpone. Would this be the result you would expect? Or should these take the new requirement date of the parent item. This would be the ideal result. Thank again for assistance

8

Hi Kerry. Basically I read what you were writing, and although there is indeed a “Phantom” Dynamic Order what the system does is uses this as a pegging point to push through to create potential purchase orders. As you were experiencing the non-updating of the postponed date to the requirement date I simply concluded you needed to set this to get it to work how you required. Why and how Microsoft intended this to work is an altogether different question [:D] Clearly it relates to upstream delays being pushed downstream in a purchase environment - should it also do this through a Dynamic Phantom Order is a different question. It could be argued both ways to be honest, and they wrote it this way! With regards to the impact on teh planning tab you will see more action messages depending upon you setting here. As you do not have it ticked for the subassemblies it would not matter in my opinion, because you see no order for this, however on the now delayed purchase order if you have the derived actions box ticked you would get a cascaded action message from the parent telling you to advance the purchase order by the number of days it has been pushed out back to the original requirement date (even though it is now using the postponed date).

I would want the alignment of all orders from the delayed parent, so I would want the futures date to impact on teh *PKP production BOMs, whilst getting teh action message to postpone I would prefer an alignment and a cascade action message to try and advance everything back to teh original requirement date (which you can see in the plan). You may want to check the basis date for the action message on the coverage group - it should be set to futures date to be honest if you are using future messaging, then you get the advance message, well you do if you have derived actions, the time fence is enough and the boxes are ticked for advance and postpone. There could be impact on the negative days here and positive days here but I will presume this are set the same as the coverage group currently otherwise you would be getting additional suggestions. So check the coverage group settings of the *PKP production BOMs and ensure the previous action message settings are set and update planning for planned orders is set in the Master Plan.

As you can see there are many many configurations here that cascade through teh plan. I would recommend you get your partner in for half a day with your current setup and ask them to trouble shoot any suggestions you are not happy with. It maybe you do not have a diverse enough set of coverage groups for your item mix, or simply that settings are not correct. However you do not seem far away by yourself to be honest [:D]

9

Hi Adam

Thanks so much for your input… I’m pleased to hear that you think we’re nearly there - what a relief! Big Smile