Phase in, phase out of an item

Hello

I am using AX 2012 R2 CU8

I have a question with respect to phase in and out of an item.  I have a situation where I am producing a product.  One of the ingredients need to be replaced (phased out) by a new, similar, ingredient (phased in).  I want AX to handle this properly, hence

• consume the phasing out item until it is available in stock
• create new purchase request for the phasing in item
• automatically switch to consume the phasing in item as soon as the phasing out item available stock is consumed

I did manage to create a setup that works well in this scenario but the issue I have is that my setup works well when the relationship between the phasing in/out items is of type 1:1 (consumption 1 kg of phasing out item is replaced by consuming a 1 kg of the phasing in item).  I cannot create a setup that automatically switches to the phasing in item when the replacement is not 1:1

I did consider to use the effective dates / create new BOM versions but this is all managed manually and not by AX.

Hope I managed to express myself well.  All thoughts are welcomed

Thanks in advance

Omar