MRP-more resources please!

High ratios of lead time to production time and nonadherences to schedule are evident in many MRP-controlled factories. An outcome of one part of the FORCAST project (aimed at reducing the nonadherences to schedules and reducing the lead time/production time ratio) is a discrete-event simulation-based scheduling toolkit called PREACTOR. Production scheduling is concerned with balancing the production capacity (the resources) required and the capacity available. The measurement of capacity available should be measured with an accuracy appropriate to that which the scheduling function requires. For example, at the level of MRP, one of the scheduling functions is to determine when material is required for purchasing. The capacity of the resources is assumed to be infinite. Production operations are loaded into time buckets (typically week by week) and the predicted load of operations on the resources is then `levelled´ to balance the capacity required to that available. The date required for material to be purchased can then be predicted