Conditions for the successful implementation of finite capacity/MRPII hybrid control systems

Manufacturing resource planning II (MRPII) is the most widely employed meth odology for production planning and control. Many authors, however, have st ated that the fundamental basis of MRPII is flawed: that is to say, schedul ing is based on fixed manufacturing lead times/lot sizes with infinite capa city. There has also been great interest in alternative methodologies such as optimized production technology (OPT) which plans to finite capacity. As a result, there are now several software houses who offer finite capacity scheduling (FCS) tools designed to operate alongside MRPII packages. These provide detailed finite capacity planning while retaining the database infr astructure of MRPII. Such hybrids claim to give the benefits of FCS to esta blished MRPII users without the need for re-implementation. This paper desc ribes the operation of such hybrids. Based on a case study drawn from the a utomotive components industry, it discusses the pitfalls that might be expe rienced without careful consideration of planning methods in relation to Bi ll of Material (BOM) structures. In particular, it shows that for a hybrid to be successful, it is necessary to consider the system as a whole, rather than considering FCS as a simple addition to MRPII.