This book seeks to give better solutions to managers managing MRP systems in manufacturing organizations. It introduces the concept of multi-pass heuristics in MRP context and shows that in variety of conditions of the shop floor (such as high and low variations in machine utilisation) these (multi-pass given in this book) can be applied to give better performance on the criterion of total aggregate (or units) lateness with insignificant rise in total costs The author explains a heuristic that modifies the holding cost (of items/assemblies that have higher difference of actual and the theoretical holding costs) and empirically shows that this is better than the heuristic that modified the lead time (of items/assemblies that have higher difference of actual and the theoretical holding costs). The book also talks about a series of heuristics that seek to attain co-ordinated arrival of assemblies at assembly centers with encouraging results