Research On Optimization Model Of Purchasing Materials For Engineering Construction With Fuzzy Demand

With the deepening of China's market economic system reform and the rapid development of economic globalization,the competition in the construction industry has become increasingly fierce,the rapid development of science and technology,but also makes the construction enterprises in the construction technology and engineering equipment on the gap is getting smaller and smaller,companies think through these areas to improve profits becomes very difficult.Most of the engineering project cost of materials accounted for more than half of the total cost,is the main cost of construction costs,so the procurement of materials should be an important part of the enterprise to reduce costs.The purpose of this paper is to establish a material purchasing decision model which is in line with the actual situation of engineering construction,and provide a scientific basis for decision making of enterprise procurement,so as to reduce the purchasing cost and improve the competitiveness of enterprises.The existing procurement model is suitable for manufacturing and retail industry.Through the study of inventory management theory and the summary of the construction cost of construction materials,it is found that although the core theory can be applied to the construction industry,but the environment of different industries and the impact of the procurement model of the relevant factors are different.In dealing with the problem of uncertainty procurement,because the manufacturing and retail industry has a certain amount of data accumulation as a supplement,so most of the them use of stochastic theory for processing.The engineering construction project as one-time activities,there is no effective historical data as a basis,so this paper decided to use fuzzy theory to deal with engineering construction materials in the uncertainty of the procurement problem.In the case of stock shortage,when the demand is fuzzy,the triangular membership function is used to discuss it,and inverse fuzzy number method is used to ambiguity resolution on inventory cost,and the optimal purchasing model is established with the fuzzy demand.When the demand rate is fuzzy,it is described by fuzzy theory,and the sign distance method and the center of gravity method are used to ambiguity resolution,and the optimal procurement model with fuzzy demand rate is established.In the case of not allowed out of stock,when the price discount model is used,the fuzzy demand is taken into account,and the price discount model under fuzzy demand is established.