Editing Material requirements planning (section)

== History ==
Prior to MRP, and before computers dominated industry, [[Reorder point|reorder point (ROP)]]/reorder-quantity (ROQ) type methods like [[Economic order quantity|EOQ (economic order quantity)]] had been used in manufacturing and inventory management.<ref>Uday Karmarkar, Getting Control of Just-in-Time, Harvard Business Review 1989</ref>

MRP was computerized by the aero engine makers Rolls-Royce and General Electric in the early 1950s but not commercialized by them. It was then 'reinvented' to supply the [[Polaris (UK nuclear programme)|Polaris program]] and then, in 1964, as a response to the [[Toyota Production System|Toyota Manufacturing Program]], [[Joseph Orlicky]] developed material requirements planning (MRP). The first company to use MRP was [[Black & Decker]] in 1964, with Dick Alban as project leader. Orlicky's 1975 book ''Material Requirements Planning'' has the subtitle ''The New Way of Life in Production and Inventory Management''.<ref>Joseph Orlicky, Materials Requirement Planning, McGraw-Hill 1975</ref> By 1975, MRP was implemented in 700 companies. This number had grown to about 8,000 by 1981.

In 1983, [[Oliver Wight]] developed MRP into [[manufacturing resource planning]] (MRP II).<ref>WJ Hopp, ML Spearman ''Commissioned Paper To Pull or Not to Pull: What Is the Question?'' Manufacturing & Service Operations Management, 2004</ref>  In the 1980s, Joe Orlicky's MRP evolved into Oliver Wight's manufacturing resource planning (MRP II) which brings master scheduling, rough-cut capacity planning, [[capacity planning|capacity requirements planning]], S&OP in 1983 and other concepts to classical MRP.<ref>{{Cite web |last=NetSuite.com |date=2020-08-12 |title=ERP: Through the Decades. |url=https://www.netsuite.com/portal/resource/articles/erp/erp-history.shtml |access-date=2023-06-01 |website=Oracle NetSuite |language=en}}</ref> By 1989, about one third of the [[software industry]] was MRP II software sold to American industry ($1.2 billion worth of software).<ref>IE. 1991. Competition in manufacturing leads to MRP II. 23 (July) 10-13.</ref>