There is no way of reserverving items considering the lead-time of items without having lots of coverage groups with different positive days representing the lead time.

The introduction of "dynamic positive days" will improve the damand planning Process as well as material availability.

For production orders the reservation strategy "Explosion" should also be available, so the reservation behaves the same as with sales orders.

Benefit of Explosion Reservation:
The Explosion reservation only reserves on-hand inventory within the dynamic positive days' time frame. If the dynamic positive days interval is bigger than the period between requirement date and master scheduling execution date, Dynamics AX reserves on-hand inventory, as there is no possibility to replenish stock. As long as items can be replenished (dynamic positive days' time frame) there should be no reservation by master scheduling.

Benefit of master scheduling calculations:
The dynamic positive time interval considers the lead times (purchase, production, transfer) of items, therefore Master scheduling generates only new planned order if a planned receipt is outside the dynamic positive time interval to fulfill the requirement. If the master scheduling execution date is within the dynamic positive days' time frame no new planned order is generated as long there is available on-hand inventory. Furthermore, the setup of Coverage groups is simplified and the number of Coverage groups could be minimized.

The setting of parameters “use dynamic negative days” and “use dynamic positive days” should be located in Coverage groups. The use of the functionalities would be more flexible, as there is the possibility to control the items differently.

The formula for calculating dynamic positive days:
Dynamic Positive days = Lead time + Positive days

Conclusion: The functionality (logic of calculation) of Positive days stays the same with the enhancement that the positive days are dynamically calculated considering the lead times (purchase, production, transfer).