Material Requirement Planning is a dependent demand system that calculates materials requirements and production plans to satisfy known and forecast sales orders. It helps to make volume and timing calculations based on an idea of what will be necessary to supply demand in the future, Nigel Slack et al (2001).

In all these definitions of Materials Requirements Planning, they all implied that it is a technique which assists a company in the detailed planning of its production. MRP translates that aggregate plan into an extremely detailed plan.