With Planning optimisation, companies that previously would have run MRP overnight now have the option to run master planning during the day, and often more than once. Planners therefore could be reviewing and firming planned orders at the same time that Planning optimisation is running, which could mean that supply for a particular demand may be replicated in the system. This can potentially mean that supply for a particular demand is doubled.

For example, a sales order creates a planned order for 10 widgets in Master Plan A. Planning Optimisation runs and regenerates a planned order for the 10 widgets. However, while it was running, a planner firmed the original planned order. When Planning Optimisation completes, it clears out the unapproved planned orders and creates the new planned orders - which would include a new planned order for 10 widgets (which was a demand without supply when MRP ran).

When looking at Master Plans, there is a history tab which shows when Planning optimisation is running for this plan ("Processing") but when firming planned orders there is no indication to the user that it is running. It would be helpful if a warning or error message showed on the client if a user goes to firm an unapproved planned order, so that they should or can wait for Planning optimisation to complete.