With Lot-for-Lot items, the reorder cycle needs to be considered when a change on the demand profile arise. As an example, we have a lot-for-lot item for which a replenishment exist which is consistent with demand profile. Now, the user changes a demand shipment date to an earlier date and the assumption is that new shipment date is within the reorder cycle. The result is that NAV suggest to Cancel the existing replenishment and creates a New one. Why?
As a general rule, it should respect the reorder cycle and reschedule the existing replenishment. However, what if an exception exists? An example is when the change on the shipment date impacts safety stock availability (stock goes below safety stock). In this case, this is an exception as well. As mentioned on an earlier post, NAV raise this as an exception so they user can decide how to address this.