Material requirements planning
Material Requirement Planning ( MRP ) is the English term for since about 1960 standard MRP .
Since the early 1970s it has been part of production planning and control systems (PPS systems), the concept of which has been described in detail as the Communications Oriented Production Information and Control System (COPICS). The PPS systems follow a phase-related successive planning concept. Based on the planning of the production program , which is derived from a sales program , this independent requirement is broken down into the secondary requirements with the help of bills of material (see Requirements Determination ). The production program is made up of already known customer orders, the results of the demand forecast and planned warehouse orders. With the help of disposition parameters (lot sizes, preliminary runs, safety stocks, etc.), the currently required material requirement is then determined.
The steps in detail were the parts list resolution with the help of so-called parts list processors (DBOMP from IBM , UNIBORS from Sperry and others). The result of the parts list explosion was the need for individual parts, sub-assemblies and assemblies for the products to be manufactured. At each disposition level of the usually multi-level parts list structure, the determined gross requirement was compared to the stock level, then the remaining net requirement ( net requirement determination ) was combined into planned production orders (lots) and further resolved. Before further dissolution, the dates of the production orders or purchase orders were roughly calculated with the help of lead times ( scheduling ). This scheduling of material requirements was based on the assumption of unlimited capacities to carry out the production orders.
The roughly scheduled production orders were then scheduled in more detail using work schedules. This lead time scheduling also provided the capacity requirements per planning period (see production planning and control ). This scheduling of the material requirement was based, like the scheduling via the BOM explosion, on the assumption of unlimited capacities for processing the production orders.
The end of the 1970s, the above procedure was followed by a capacity scheduling to, among other things, with the aim of avoiding congested capacity in individual planning periods realistic dates for the planned production orders to obtain. This is now MRP I called.
Manufacturing Resources Planning with the abbreviation MRP II is a further development and expansion of material requirements planning .
Due to the weaknesses of MRP-II, the Advanced Planning System was developed around the year 2000 , which is subdivided into individual modules that are related to one another and which thus deviates from the successive method of MRP-II.
literature
- H. Stadler C. Kilger (Ed.): Supply Chain Management and Advanced Planning . 3. Edition. Springer Verlag, Berlin / New York 2005, ISBN 3-540-74511-4 .
Individual evidence
- ^ H. Stadtler, C. Kilger (Ed.): Supply Chain Management and Advanced Planning. Berlin 2005.