Suppliers belong to an open system of the supply chain, so the choice of suppliers will also be affected by various economic, political and other factors.

1.1 Quality factors

Quality is the basis of the survival of the supply chain. The use value of products is based on product quality.
 It determines the quality of the final consumer products and affects the market competitiveness and share of products.
 Therefore, quality is an important factor in choosing suppliers.

1.2 Price factors Low prices mean that enterprises can reduce the cost of their production and operation, 
which has an obvious effect on improving competitiveness and increasing profits for enterprises, and is an important factor in choosing suppliers. 
But the supplier with the lowest price is not necessarily the most suitable, but also needs to consider many factors such as product quality, 
delivery time and transportation costs.

1.3 On-time delivery factors

Whether the products can be delivered on time according to the agreed time and place directly affects the continuity of production and supply 
activities of the enterprise. It will also affect the inventory level of the supply chain at all levels, which in turn affects the speed of the company's 
response to the market, interrupting the production plan of the manufacturer and the sales plan of the seller.

1.4 Variety flexibility

In order to survive and develop in the fierce competition, the products produced by enterprises must be diversified to meet the needs of consumers, 
to achieve the purpose of occupying the market and obtaining profits. The diversification of products is based on the variety flexibility of suppliers, 
which determines the types of consumer products.
1.5 Other influencing factors

Including factors such as design capabilities, special process capabilities, overall service levels, and project management capabilities.

According to a research survey on the topic of "CIMS-Supply Chain Management" in 1997, the data shows that when Chinese companies choose suppliers, 
the main criterion is quality, and about 98.5% of companies consider quality factors, followed by price.

Among these five, the quality factor is the most important. First of all, we must confirm whether the supplier has established a stable and effective 
quality assurance system, and then confirm whether the supplier has the equipment and process capabilities to produce the specific products required.

The second is cost and price. It is necessary to use value engineering methods to analyze the cost of the products involved, and achieve cost savings 
through win-win price negotiations. In terms of delivery, it is necessary to determine whether the supplier has sufficient production capacity, 
whether human resources are sufficient, and whether there is potential for expanding production capacity.