Four modes of purchasing logistics and purchasing principles are briefly described.

Five principles of procurement: (principle of appropriate price) (principle of appropriate quality) (principle of timely) (principle of appropriate quantity) (principle of appropriate location).

Four modes of purchasing logistics:

(1) Traditional procurement mode: based on the purchase application plan of each unit, with the purpose of replenishing inventory, the management is relatively simple, and it is easy to cause problems such as large inventory, overstocked funds and high inventory risk. Due to the above characteristics, this procurement model is not recommended by enterprises.

(2) Order-point procurement mode: it is divided into order-based procurement and regular order-based procurement.

Ordering by quantity: it 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. Conventional non-important products and scarce non-important products are suitable for this model.

Regular order purchase: it is to determine an order cycle and a maximum inventory level in advance, and then take the specified order cycle as the cycle, regularly count the inventory and issue orders. The order batch size is not necessarily the same every time, and the order quantity is equal to the difference between the actual inventory at that time and the specified maximum inventory level. Conventional important products and scarce important products are suitable for this model, and scarce non-important products and scarce important products can also adopt this model.

(1)MRP mode: MRP procurement is carried out by enterprise procurement personnel using application software to make procurement plans. This model is suitable for manufacturing enterprises with high degree of informatization and good cooperative relationship with suppliers.

(2)JIT mode: Just-in-time procurement is a procurement method based on fully meeting the demand. What users need, how much, when and where, we must meet the needs of customers. This model is suitable for manufacturing enterprises with high degree of informatization and good cooperative relationship with suppliers.

(3)VIM procurement mode: VIM managed inventory, whose basic idea is that under the supply chain mechanism, procurement is not operated by buyers, but by suppliers. VMI procurement is such a procurement mode. Users only need to continuously and timely transmit their own demand information to suppliers, and suppliers themselves predict their future needs according to their own demand information, and make their own production plans and delivery plans according to this predicted demand. The inventory size of users is determined by suppliers themselves. This model is suitable for purchasing enterprises with high information level, and the suppliers they cooperate with have a very high level of business operation.

(4) E-procurement mode: E-commerce procurement online procurement is a procurement mode under the e-commerce environment. Its basic principle is that purchasers can find suppliers and required varieties online, negotiate trade online, order online or even pay for goods online, and finally realize delivery or purchase operations and complete all procurement activities. Online procurement is a promising procurement model, which can expand the scope of procurement market, shorten the distance between supply and demand, simplify procurement procedures, reduce procurement time, reduce procurement costs and improve work efficiency. This model is suitable for enterprises with high degree of informationization and high level of logistics and distribution.