MRP adopts ABC classification of materials, that is, the phenomenon of "20-80'" in Pareto principle, and handles the inventory of different materials differently. That is to say, in most enterprises, the total value of materials accounting for about 20% of varieties accounts for about 80% of the total value of materials in the factory, while the total value of materials accounting for about 80% of varieties accounts for only about 20% of the total value of materials in the factory.
2, cycle inventory
In MRP system, besides the usual period counting method, the period counting method can also be used. Cycle inventory is an optional verification method, which is often adopted by high-tech industries. Cycle counting treats different types of materials A, B and C differently, stipulates different counting intervals and allowable counting errors, and takes turns counting. The advantage of periodic counting is that it can be counted without interrupting production. In order to ensure accurate inventory, fixed location management is the premise, and the relationship between warehouse, location, batch number, container or pallet and materials must be clarified. Cycle counting can also be called cycle counting or cycle counting.
Cycle counting is just a method of inventory counting. Its spirit is to reduce the impact of inventory on normal production and treat inventory demand differently according to the value of materials. However, inventory is only a post-event processing method, which can only find problems and correct mistakes. In a sense, this is a tedious and annoying job, and it is also a waste of manpower. It is important to find out the causes of errors through circular counting, improve and perfect the inventory management system, and strictly follow the working procedures to avoid errors. Otherwise, even if the interval of inventory in table 18.3 is shorter, it will not help to improve the accuracy of inventory records.
3. Maintain the accuracy of inventory information.
Inventory information is one of the three main input data for running MRP, and its accuracy must be guaranteed. The usual practice is as follows.
(1) Train and educate relevant managers, make clear the necessity of accurate inventory records, and know how to ensure the accuracy of inventory data.
(2) Establish a responsibility system with serious working principles and procedures, and each inventory transaction must be entered into the retail system within the specified time.
(3) Manage the historical files of inventory transactions.
(4) The layout of the reservoir area is reasonable, the storage facilities are convenient for storage and inventory, and the management is strict. People and things entering and leaving the warehouse have strict rules and regulations.
(5) Conditional warehouses should use bar codes and automatic identification facilities as far as possible to automatically record the number of warehousing online.
(6) Regularly review and announce the accuracy of the inventory data of the responsible persons in the reservoir area, with clear rewards and punishments.
To ensure the accuracy of inventory information, the material management department has the responsibility to maintain it, and the design, planning and cost departments should also pay attention to it. The design department should maintain the bill of materials, the planning department should maintain the demand of materials, and the cost department should maintain the standard cost of materials, which are directly related to the accuracy of inventory information. In the integrated e-commerce system, inventory management is not an isolated operation.