Master scheduling has to deal with an increasing number of transactions, especially if a company goes through a lean transformation. The lean transformation leads to shorter lead times and smaller batch-sizes. Having reached the ideal of batch size one may suddenly increase the number of transactions that master scheduling deals with by factor 10 to 100.
This is especially true if your configuration is set for your operative scheduling - usually covering few weeks, or in the lean ideal a few days. But if you use the same configuration to calculate your tactical plan, that usually spans over a couple of month up to a year, the volume of transactions can be considerable. At a customer review we found more than 7000 planned transactions for a category C part - a part that should be planned on minimum stock level instead.
In a meeting I had with the planning team of the customer, it became transparent, that one of the challenges is to configure the lead times as well as the positive and negative days for master scheduling. You need to start with analyzing how demand patterns of different products and materials behave. Unfortunately, the formula "longer is better" does not apply here. Having 200 planned purchase orders in the future for an item that has a purchase lead time of only few days is - in lean terms - waste.
To limit the runtime of master scheduling on one hand and the number planned orders and action messages on the other side, It is recommended to work with 2 different plans:
It is recommended to structure the coverage groups by demand patterns and use item coverage only to punctually override settings for products, that require special treatment or to evaluate modified behavior.
Negative / Positive days:
For the improvement of the settings of the operational plan the following guidance should be considered:
Master scheduling with Microsoft Dynamics AX is truly a dynamic task. There are many ways of influencing the planning results and the performance of master scheduling by modifying the right parameters. The resulting plan can only be as good as the configuration allows - and of course, dependent on the quality of the actual and the forecasted demand. We would love to hear about your experiences and your best practices related to positive and negative days and Dynamic negative days. We are also interested in your experiences with multi-plan strategies.
Meet the Microsoft Dynamics AX manufacturing team at the AXUG Summit next week or at Microsoft Dynamics AX Technical conference 2012 in the manufacturing focus room.