There are many technical methods (also called quantitative analysis methods) to choose from in cost analysis. Enterprises should determine which method to use for cost analysis according to the purpose of analysis, the characteristics of the analysis object and the information they have. In practical work, there are three commonly used technical analysis methods: comparative analysis, factor analysis and correlation analysis.

1, comparative analysis method

Comparative analysis is a method to reveal the differences and analyze the reasons by comparing the actual cost indicators with the indicators in different periods. In the comparative analysis, the actual indicators can be compared with the planned indicators, the actual indicators of the current period and the previous period (or the same period last year, the best level in history), and the actual indicators of this period can be compared with the advanced indicators of the same type of enterprises at home and abroad. Through comparative analysis, we can get a general understanding of the rise and fall of enterprise cost and its development trend, find out the reasons, find out the gap and put forward further improvement measures. When using comparative analysis method, we should pay attention to the comparability of actual indicators and comparative indicators in this period, so that the results of comparison can better explain the problem and reveal the differences in line with reality. If there is no comparability, the analysis result may be inaccurate, and even the opposite conclusion completely different from the actual situation may be drawn. When using comparative analysis method, we can take various forms such as absolute number comparison, increase and decrease difference comparison or relative number comparison.

Comparative analysis method according to the comparison content (than what) is divided into:

(1) Total amount of comparative accounting elements

(2) Comparative structural percentage

(3) Comparative financial ratio

2. Factor analysis method

Factor analysis is an analytical method to decompose a comprehensive index into interrelated factors and determine the influence of these factors on the difference of comprehensive index. The application of factor analysis method in cost analysis is to decompose various factors that constitute the cost, measure the influence degree of each factor change on the completion of the cost plan, evaluate the implementation of the enterprise cost plan accordingly, and put forward further improvement measures.

The steps of factor analysis are as follows:

(1) decompose an economic indicator to be analyzed into the product of several factors. When decomposing, we should pay attention to the components in economic indicators that can reflect the internal reasons for the differences of indicators, otherwise the calculation results will be inaccurate. For example, the material cost index can be decomposed into the product of product output, unit consumption and unit price. But it can't be decomposed into the product of the number of days to produce the product, the materials consumed every day and the product output. Because this composition can not fully reflect the composition of product material cost.

(2) Calculate the actual number and base period number of economic indicators (such as planned number and previous period number, etc.). ), thus forming two index systems. The difference between these two indicators, that is, the difference between the actual indicators and the base indicators, is the object to be analyzed. The total influence of various factors on the completion of the economic indicators to be analyzed should be equal to the analysis object.

(3) Determine the substitution order of each factor. When determining the composition of economic index factors, its order is the substitution order in analysis. When determining the substitution order, we should proceed from the interdependence of various factors, so that the analysis results can help to distinguish economic responsibilities. The general replacement order is to replace the quantity index first, and then replace the quality index; Replace the physical quantity index first, then replace the monetary quantity index; Replace the main indicators first, and then replace the secondary indicators.

(4) Calculate the substitution index. Its method is based on the number of base periods and gradually replaced by various factors in the actual index system. Every time you replace a factor in the cardinal index with an actual number, you can calculate an index. Keep the actual number after each replacement, and replace several factors several times to get several indicators. Pay attention to the replacement sequence when replacing, and adopt serial mode without interruption. Otherwise, the sum of the influence degrees of calculation factors cannot be equal to the difference between the actual number of economic indicators and the number of base periods (that is, the analysis objects).

(5) Calculate the influence of various factors on economic indicators. The method is to compare the results of each substitution with the results before the substitution of this factor, and the difference is the degree of influence of the change of this factor on economic indicators.

(6) The sum of the influences of various factors on economic indicators should be equal to the difference between the actual number of the economic indicators and the number of base periods (that is, the analysis objects).

The calculation process of the above factor analysis method can be expressed by the following formula:

Let an economic index n be composed of three factors: A, B and C. In the analysis, if the actual index is compared with the planned index, the calculation formula of the planned index and the actual index is as follows:

Planning index N0=A0×B0×C0

Actual index n1= a1× b/kloc-0 /× c1.

The analysis object is the difference of N 1-N0.

When determining the influence degree of each factor change on index n by factor analysis, the calculation formulas of each planned index, actual index and substitute index are as follows:

Planning index N0 = A0× B0× C0-(1)

For the first time, N2 = A 1× B0× C0-(2)

The second substitution n3 = a 1xb 1xc0-(3)

Actual index n1= a1× b/kloc-0 /× c1-(4)

The influence of each factor change on the index n is calculated as follows:

Because of the change of factor A =(2)-( 1)=N2-N0.

Because of the change of factor b =(3)-(2)=N3-N2.

Because of the change of factor c =(4)-(3)=N 1-N3.

The sum of the above three items, that is, the degree of influence of various factors on the index n, should be equal to the analysis object.

According to the substitution principle of factor analysis, the substitution order of material cost is output, unit consumption and unit price. The calculation results of various factors that the material cost of product A is actually 8 000 lower than planned are as follows:

Planned material cost =250×48×9= 108 000 (yuan) -( 1)

First substitution = 200×48×9 = 86400 (yuan) -(2)

Second substitution =200×50×9=90 000 (yuan) -(3)

Actual material cost = 200× 50×10 =100000 (yuan) -(4)

The effects of various factors on reducing the material cost by 8,000 yuan are as follows:

Influence of output change on material cost = (2)-(1) = 86400-108000 =-21600 (yuan)

Due to the change of material consumption, the impact on material cost =(3)-(2)=90000-86400=3600 yuan.

Due to the influence of material unit price change on material cost = (4)-(3) =100000-90000 =10000 (yuan)

The influence degree of the three factors on the material cost =-21600+3600+10000 =-8000 (yuan).

In the above analysis and calculation, another simplified form can be adopted, that is, the difference calculation method. The difference calculation method is to use the difference between the actual number of each factor and the number of base periods to directly calculate the influence degree of each factor change on economic indicators. Taking the above-mentioned economic index n as an example, the calculation formula when using the difference calculation method is as follows:

The influence of the change of factor A on the index =(A 1-A0)×B0×C0.

The influence of the change of factor B on the index =A 1×(B 1-B0)×C0.

The influence of the change of factor c on the index = a/kloc-0 /× b/kloc-0 /× (c1-c0).

[Example 3] Based on the analysis data of the material cost of Example 2, the result of the variance calculation method is as follows:

Due to the increase of output, the impact on material cost =(200-250)×48×9=-2 1600 (yuan)

Influence of material consumption change on material cost =200×(50-48)×9=3600 yuan.

The influence of material unit price change on material cost = 200× 50× (10-9) =10000 (yuan)

Influence of various factors on material cost =-21600+3600+10000 =-8000 (yuan)

The calculation results of the two methods are the same, but the difference calculation method is obviously much simpler than the first method.

3. Correlation analysis method

Correlation analysis refers to the method of analyzing the correlation between related but different indicators when analyzing an indicator. There is an interdependent relationship among the economic indicators of enterprises. In these indicator systems, if an indicator changes, the related indicators affected by it will also change. If the profit index is compared with the product sales cost and the cost profit rate index is calculated, the level of enterprise cost and income can be analyzed. For another example, the change of product output will lead to the corresponding change of cost, and the correlation analysis method is used to find out the regular relationship between related indicators, thus serving the cost management of enterprises.

4, the difference calculation method

The difference calculation method is a simplified form of factor analysis method, which uses the difference between the target value and the actual value of each factor to calculate its impact on the cost.

5. Ratio method

Ratio method refers to the method of analyzing with the ratio of more than two indicators. Its basic characteristics are: first, the comparative analysis values are turned into relative numbers, and then the relationship between them is observed. The commonly used ratio method is as follows.

● Correlation ratio method Because all aspects of project economic activities are interrelated, interdependent and influential, we can find out the ratio by comparing two different and related indicators, so as to examine the quality of operating results. For example, output value and wages are two different concepts, but the relationship between them is the relationship between input and output. Under normal circumstances, everyone wants to achieve the maximum output value with the least wage expenditure. Therefore, it is very telling to use the output value wage rate index to assess the expenditure level of labor costs.

The composition ratio method is also called specific gravity analysis or structural comparison analysis. Through the composition ratio, we can examine the composition of the total cost and the proportion of each cost item to the total cost, and at the same time we can see the proportional relationship among quantity, cost and profit (that is, the proportional relationship between budgeted cost, actual cost and cost reduction), thus pointing out the direction for seeking ways to reduce costs.

● Dynamic ratio method The dynamic ratio method analyzes the development direction and speed of this indicator by comparing the values of similar indicators in different periods and finding out the ratio. The calculation of dynamic ratio usually adopts two methods: base period index and ring index.