The calculation steps of factor analysis method: determine the analysis object and calculate the difference between the actual number and the target number; Determine which factors the indicators are composed of, and sort them according to their mutual relationship (the sorting rules are: physical quantity first, then value quantity; First value, then relative value); Based on the target number, multiply the target number of each factor as the basis for analyzing substitution; Calculate the actual number of each factor according to the above arrangement order, and keep the actual number after replacement; Comparing the results of each substitution calculation with the previous calculation results, the difference between them is the degree of influence of this factor on the cost; The sum of the influence degree of each factor should be equal to the total difference of the analysis object.

1. Factor analysis. Also known as empirical analysis, it is a qualitative analysis method. This method mainly refers to determining the selected object through collective research on the basis of various factors that should be considered in the selection of value engineering objects and the knowledge and experience of analysts. This method is simple, requires value engineers to be familiar with products and have rich experience, and is suitable for situations where the research objects are quite different or the time is short. The disadvantage is that there is no quantitative analysis and the subjective influence is great.

2. Factor analysis is a statistical analysis method to analyze the influence degree of each factor in the total change of phenomenon by using statistical index system, including sequence substitution method, difference analysis method and index decomposition method. Factor analysis is an important and practical method in modern statistics and a branch of multivariate statistical analysis. Using this method, researchers can simplify a set of variables that reflect the nature, state and characteristics of things into a few factors that can reflect the internal relations of things and determine the essential characteristics of things.

3. By analyzing the supply and demand situation of futures commodities and its influencing factors, the method to explain and predict the changing trend of futures prices. Futures trading is based on spot trading. There is a close relationship between futures price and spot price. The supply and demand of commodities and many factors affecting their supply and demand have an important impact on the commodity price in the spot market, and therefore will inevitably have an important impact on the futures price. Therefore, by analyzing the changes of commodity supply and demand and its influencing factors, it can help futures traders predict and grasp the basic trend of commodity futures price changes. In the real market, futures prices are not only affected by the relationship between supply and demand of commodities, but also by many other non-supply and demand factors. These non-supply and demand factors include: financial and monetary factors, political factors, policy factors, speculative factors, psychological expectations and so on. Therefore, the analysis of the basic factors of futures price trend needs to comprehensively consider the influence of these factors.