Master planning (MRP) module in Dynamics 365 F&O and Infor LN

Dynamics 365 F&O and Infor LN both employ master planning to forecast future demand and determine optimal order quantities. The main difference lies in one setting: the coverage time fence, which affects replenishment costs. The coverage time fence is a number of days that master planning reads supply and demand. If it falls short of the longest purchasing lead time, there is a loss in fill rate, but no error is raised.

For every day below the lead time, the coverage time fence costs about half a point of service. Doubling the window removes approximately 39% of purchase orders and adds 126% to stock, with unchanged fill rate. The ideal window length varies by business. Five business cases were built from two years of a UK wholesaler's order lines, with both products showing similar performance.

The floating window was the most effective method in all cases. Neither product includes the other's full set of features, such as fixed order quantity and economic order quantity in Infor LN, and priority-based replenishment and decoupling point in Dynamics 365 F&O. The coverage time fence is the key factor to tune in master planning, and its value depends on the specific business needs.