| Manufacturing Resource Planning (MRP II) was designed to provide an executable master production schedule of all dependent parts or materials under limited resource availability. Current logic of MRP II systems depends on an iterative process and feedback to find feasible schedule under the limits of resource capacity. It considers only sequential manufacturing and ignores concurrent or simultaneous processing. Finding a feasible schedule is not sufficient in today's highly competitive and modern manufacturing environment. The manufacturing lot-sizing scheme under MRP II can be described as a multi-level, multi-item, and multi-resource capacitated lot-sizing problem {dollar}rm (Msp3CLSP).{dollar} Traditional lot-sizing algorithms can not provide a proper lot-sizing plan under these environment.; In this research, the formal definition and related issues of Concurrent Processing (CP) are presented. A linear analytical model is developed to provide an optimal MRP II plan in terms of manufacturing resource and material holding costs. Concurrent processing contributes to finding an efficient global feasible solution. Linear Programming (LP) is used to find a global optimal solution. Two-phased heuristics for finding order quantities for fixed-lot size or lot-for-lot lot-sizing are developed. The heuristic algorithms use backward/forward searches and merging of quantities to reach a good plan.; A comprehensive computer based system, VisualMRP, which includes Material Requirements Planning (MRP) and Manufacturing Resource Planning (MRP II), and is based on the presented techniques; is developed. VisualMRP is a Microsoft {dollar}rm Windowssp{lcub}TM{rcub}{dollar} based which makes use of MS productivity tools, such as MS Access, and MS Excel. It has a user friendly interface with familiar pull-down menus and image toolbars with tooltips. This makes an ideal system for use by practitioners seeking optimality in the manufacturing environment. |
