What purchasing modes do enterprises generally have?

Reprint the following information for your reference.

Procurement mode

First, the traditional procurement model is based on application and aims at filling inventory. The inventory is overstocked for two years. The purchase mode of order point is that the purchaser determines the order point, order batch or order cycle and the highest inventory level of each variety according to the demand of each variety and the lead time of the order, and then establishes the inventory inspection mechanism. When the ordering point is found, the inventory is checked and the order is issued. The size of the order batch is determined by the prescribed standards. Ordering point procurement includes two major procurement methods, quantitative ordering method and regular ordering method. Quantitative ordering method is to determine an order point and an order batch in advance, and then check the inventory at any time. When the inventory drops to the order point, the order is issued, and the size of each order batch is the same. Regular order method is to determine an order cycle and the highest inventory level in advance, and then take stock of the inventory regularly and order according to the specified order cycle. The order batch is not necessarily the same every time, and the size of the order batch is equal to the difference between the actual inventory at that time and the specified maximum inventory level. The purchase mode of order point is based on demand analysis, aiming at filling inventory, adopting some scientific methods, giving consideration to meeting demand and controlling inventory cost, with scientific principle and simple operation. However, due to many random factors in the market, this method also has the defects of large inventory and insensitive market. Thirdly, MRP procurement mode is mainly used in production enterprises. It is realized by purchasing personnel of enterprises using MRP software to make purchasing plans. The principle of MRP procurement is to gradually calculate the production time and quantity, or order time and quantity, of all parts and raw materials of the main product according to MPS (master production plan) and BOM (bill of materials or product structure file) and the inventory of the main product and its parts, that is, to generate the production plan and procurement plan of all parts and raw materials. Then make a purchase according to this purchase plan. MRP purchasing mode is also based on demand analysis, aiming at meeting inventory. Because the plan is more detailed and strict, its market sensitivity and inventory level are improved compared with the above methods. Fourth, JIT procurement mode JIT procurement, also known as just-in-time procurement, is a procurement method based entirely on meeting demand. The demander sends an order to the supplier according to its own needs, requiring the supplier to deliver the specified variety and quantity to the specified place within the specified time. JIT procurement realizes sensitive corresponding market, meets users' needs and minimizes users' inventory. Because users do not need to set up inventory, realize zero inventory. It is a scientific and ideal purchasing model. 5. The basic idea of VMI (Vendor Managed Inventory) is that under the supply chain mechanism, procurement is no longer operated by the purchaser, but by the supplier. VMI procurement is a procurement mode. Users only need to transmit their own demand information to suppliers in time, and suppliers can predict their future demand according to their own demand information, and make their own production plans and delivery plans according to this prediction. The inventory size of users is determined by suppliers. It is an ideal and scientific procurement model, and the biggest beneficiary is the user. However, supply chain procurement has high requirements for enterprise information systems and suppliers' business operations. 6. E-procurement mode E-procurement, that is, online procurement is a procurement mode under the e-commerce environment. For example, It is a promising procurement mode, which simplifies procedures, reduces procurement time, reduces procurement costs and improves work efficiency. Relying on the development of e-commerce and the improvement of logistics distribution level