Implementation of MRP:

In general, in product focused system, raw material ordered exactly to the finished good requirement, is instantaneous corrected into the system product.

MRP delivers the most benefits to process-focused systems that have long processing times and complex multistage production steps due to its complex inventory and production planning. Picture of hypothetical production system which converts raw materials into finished goods instantaneously, is the case in some simple product-focused systems. Raw materials would be ordered in to exactly match finished-goods requirements. In process-focused systems, the in-house processing lead times exceed the lead times needed to obtain the raw materials from suppliers. MRP's ability planned order receipts to account for long lead times and complex production processing steps very much simplifies production and inventory planning. MRP is conventionally applied only to manufacturing systems. This means that MRP is seldom applied to service systems, retailing systems, petroleum refineries, transportation firms, and other non-manufacturing systems. Many believe that MRP may be successfully applied to some of the non-manufacturing systems. When service systems require sets of raw materials to deliver one unit of service, MRP potentially can be applied. Surgical operations in large hospitals, high-volume professional services, and other processes are likely to use MRP systems in the future.

Implementation of an MRP system is not a painless process. Because MRP is an information system that is driven by information, merely buying software and possibly some hardware does not guarantee a successful MRP system. There are some significant start up costs and some ongoing costs in implementing an MRP system. Many of these costs are associated with rectifying poor or inadequate information as well as instituting system discipline to ensure that correct information continues to flow into the MRP system. These are usually hidden costs that are often not recognized formally when the proposal for an MRP system is presented.