ЗАСТОСУВАННЯ МЕТОДУ ЛІНІЙНОГО ПРОГРАМУВАННЯ В ПРОЦЕДУРАХ ПЛАНУВАННЯ MRP II

Abstract

The assimilation of modern approaches to enterprise management in Ukraine is rather slow, contrary to the rapid development of programming tools and informatics in general. Transparency, predictability, implementation of generally recognized management processes contribute to the efficiency of enterprises. The widely known methodology of Manufacturing Resource Planning II (MRP II) can ensure the operation of the enterprise without shortages of materials and equipment. The MRP II standard describes the processes of the management system, which cover all phases of management: planning, organization of activities, accounting and rationing. For these processes, a set of procedures and methods that must be implemented is presented. Taking in account the high demands of MRP II on enterprise organization and computing resources, an attempt was made to improve this process by applying optimization method, such as linear programming, to the central link of the process, which is the formation of the Master Production Shedule. Planners still perform these processes, but in most cases not formalized, so it would be useful to offer them some formalized options for building a Master Production Schedule within the framework of the MRP II methodology. In the MRP II methodology, which is the de facto industry standard, during formation of the Master Production Schedule, in addition to the requirement for the MPS to meet the sales plan, the limitations that should affect the formation of the MPS are, first of all, limitations on the capacities of equipment (work centers) and limitations on the availability of materials, taking into account the duration of the procurement cycles of this or that material. The standard algorithm involves checking the constraints only after the MPS is formed, and if the latter violates some constraints, organizational measures must be taken to correct the situation (such as accelerated delivery of materials or the rental of additional equipment, which incurs additional costs), or the MPS must be redesigned. Instead, the authors suggest taking into account critical limitations already in the process of MPS formation. This is possible thanks to the formulation of constraints within the linear programming problem. In this case, if, for example, equipment capacity limitations are active, the linear programming algorithm from the very beginning distributes the production of product types to earlier planning intervals, smoothing the peak load on the work centers. Several strategies for scheduling manufacturing inventory replenishment are considered, such as replenishment to offset each sale; periodic replenishment; maximum top-ups as much as the limits allow. Proposed template in the form of spreadsheet for a better understanding of MPS construction options.