(BY AMT ERP Research Group)
MRP basic composition
(1) Master Production Schedule, Abbreviation MPS
The main production plan is to determine the number of plans to produce each specific final product in each specific time period. The final product here refers to the final completion of the company, and it is necessary to go to the factory, it should be specific to the product's variety, model. The specific time period here is usually in a week, in some cases, can also be a day, twelve, month. What is the production plan for the main production plan, what time should be output, it is an independent demand plan. The main production plan is embodied according to customer contract and market forecast, which makes the product line in the business plan or production, making it the main basis for the development of material demand plans, and has enabled from the integrated plan to carry out the transition of specific plans.
(2) Product Structure and Material List (BILL of Material, BOM)
The MRP system should correctly calculate the time and quantity of material demand, especially the quantity and time of the relevant demand materials, first enable the system to know the product structure manufactured by the company and all materials to be used. The product structure lists the composition, assembly and quantity requirements of all components, components, parts, etc. constituting the finished or assembly. It is the foundation of MRP product demolition. For example, the following figure is a greatly simplified bicycle product structure, which generally reflects the composition of the bicycle:
Figure 1 Bicycle product structure diagram
Of course, this is not the BOM we want. In order to facilitate computer recognition, the product structure map must be converted into a standardized data format, which describes the product structure with a specified data format is a list of materials. It must explain the number of various material requirements in the component (part) and the composition structure relationship between mutualities. The following table is a list of materials corresponding to the structure of the bicycle product structure.
Table 1 Material list of bicycle products
Note: "M" in the type is self-cultivated, "b" is purchased.
(3) Inventory information
Inventory information is a database that saves all companies, components, in the presence of presence of products, raw materials, and the like. In the MRP system, the products, components, collectively referred to as "materials" or "project" in products, raw materials, and even tooling tools. In order to facilitate computer recognition, the material must be encoded. Material coding is the unique identifier of the MRP system identification material.
1 Existing stock: refers to the amount of inventory of materials that are actually stored in the enterprise warehouse.
2 Program receiving amount (in the way): means that the material will be stored in the future according to the purchase order or production order in progress, and the number of materials will be completed in the future. 3 Distributed quantity: means the number of materials whose still saved in the warehouse but has been assigned.
4 Adjust: means that an task is executed by the start to complete. 5 Order (Production) Batch: Order the supplier or require the production department to produce a certain amount of material in a certain period.
6 Safety inventory: In order to prevent the unpredictable fluctuations in demand or supply, the minimum inventory number should often be maintained in the warehouse as a safe stock.
According to the above values, the net demand for a material can be calculated:
Net demand = Mao demand allocated quantity - planned receipt - existing stock
