Visit MRP (Material Requirements Planning), or Component Requirements Planning, is an information and inventory management system designed to determine which raw materials and components are required, in what quantity and when to produce a finished product according to the established production plan.
In-depth definition : MRP is the heart of planning in a production system. Flux Poussé (Push System). It uses Bill of materials (BOM) of the product (list of components), the Master Production Plan (MPP) (what needs to be manufactured and when), and the state of stocks (which is already available) to generate purchase orders raw materials and production orders in-house. Its main role is to ensure that materials are available when needed for production, while minimizing inventory costs and stock-outs.
The Three Fundamental Inputs of the MRP System
To calculate production requirements, MRP relies on three sources of structured, integrated data, often managed via a system ERP (Enterprise Resource Planning) :
A. Master Production Plan (MPP)
- Role : This is the highest level of planning. It indicates the demand for finished products over a given period (often 6 to 18 months). MPS is based on sales forecasts and firm orders.
B. Bill of Materials (BOM)
- Role : MRP needs to know the tree structure and the exact quantity of each component and sub-assembly required to assemble a unit of finished product. An accurate BOM, often derived from the’Industrialisation and formalized in the Manufacturing file, is essential for accurate calculations.
C. Inventory Status File
- Role : It records current stock levels for each item, including physical stocks, quantities on order, and quantities already allocated to other production orders.
MRP calculation and execution
The MRP system performs a calculation by fragmented needs (called Nettage). It starts with the gross requirements for finished products (from the PDP), deducts what is already in stock (B), and uses the BOM to calculate the dependent requirements for sub-assemblies and raw materials. The final result is a set of recommendations:
- Planned Production Orders : For components manufactured in-house (with the necessary launch and delivery dates).
- Planned Purchase Orders : For raw materials and parts purchased from suppliers (with necessary order and receipt dates).
MRP, Digitization and Performance Improvement
Although MRP is intrinsically linked to the Flux Poussé, optimization is essential for any manufacturing company:
- Rupture Reduction : The main objective of MRP is to ensure the availability of parts at the time of production, eliminating wastage (Muda) criticism: waiting due to lack of material.
- Planning optimization : The engineers at Industrial Engineering can use MRP to simulate the impact of changes in demand or supply on the Manufacturing range, helping to identify potential overload periods and Choke bolts in the value chain.
Evolution to MRP II (Manufacturing Resource Planning)
MRP has evolved into MRP II, which is a much more comprehensive system, integrating not only materials, but also production capabilities (Capacity Requirements Planning - CRP). MRP II seeks to validate whether the company has not only the parts, but also the machine time and human resources needed to execute the plan, thus providing a more global view of the company's business.’Operational Excellence.
Link with Manufacturing Execution Systems (MES)
MRP generates production orders for finished products. These orders are then transmitted to the MES (Manufacturing Execution System), who is responsible for detailed execution on the shop floor, data collection via the’IoT, and real-time monitoring. MRP and MES form the planning and execution loop in the digital architecture.
The role of the digital transformation consultant
Incorrect MRP implementation or configuration leads to poor inventory sizing (too much unnecessary stock or shortages). The digital transformation consultant also intervenes to :
- Making the BOM more reliable: Ensuring the accuracy of Parts list and Manufacturing file.
- Optimize Settings : Define the right lead times and batch sizes (often smaller, to achieve the best possible results). Pulled Flow when possible) and safety stock policies.
- Align planning and execution : Ensure that MRP and MES communicate correctly for decision-making based on reliable data.
In conclusion, the MRP is the mathematical tool that manages the “when” and “what” of procurement. Mastering it is essential to transform planning into smooth, profitable execution.