MRP implimentation experiences

Not sure this is the best forum for this, but here goes:

I’m looking for people willing to discuss their implementation experience. We are a manufacturing company that last year went live with Quotes and Sales orders (AX4) that interfaced to 2 separate legacy systems ( US and Europe) and now will be adding the complete MRP processes in all of our plants. How close to go-live did you let your customers know that you were changing your MRP system? What kind of feedback/push back did you get from them? Any other information would be appreciated.

I do not think customers care if you changing your system - especially MRP.

I think they care if you changing your manufacturing policy – let say go from Make-To-Stock to Make-to-Order. If you do not expect increase in the customer lead time you do not need to notify them.