Sales cost forecast of auricularia auricula industry?

(A) One-dimensional linear regression method

The prediction method of linear regression has been described in the third section. This method is suitable for cost forecasting in the period of small price fluctuation. If the price fluctuates greatly, the price caliber should be converted. The specific method is as follows.

2. Convert the project cost of the preparation year into the cost level of the forecast period.

3. Establish a regression prediction model.

(b) Time series analysis and prediction

1. Calculate the unit square cost of similar construction projects in each year.

Generally, a construction enterprise will have several projects of the same type completed in the same year, and the cost of unilaterally compiling a construction project is inconsistent. In addition, many projects are built across years. If the forecast period is one year, their cost actually reflects not only the cost level of this year. To solve these problems, the following methods can be used for calculation:

(1) usually takes one year as a forecast period;

(2) The actual cost of the inter-annual project is taken as the cost data of the completed year;

(3) There are several similar projects completed in the same year, and the average value is taken as the actual cost value of that year.

2. Forecast the cost of next year by time series analysis.

After calculating the annual average single cost of similar projects in previous years, we can use any time series analysis method to predict the single cost of similar projects in the next year.

The specific calculation method has been specially introduced in the last section. Here, we suggest to use the exponential smoothing method for calculation, because the result of exponential smoothing method is closer to the actual value than other methods, and it is suitable for short-term and medium-term forecasting.

(3) Exponential curve regression method

In order to judge the future value that develops and changes in a certain proportion year by year, it is necessary to use the exponential curve trend prediction method to predict. In recent years, due to the rapid development of economy and the liberalization of national prices, the price has increased at a rate of about 10% year by year, and the construction cost has also shown a similar trend. Therefore, in view of this situation, the exponential curve regression method can be used to predict.

Second, the detailed prediction method

This prediction method is usually to analyze the factors that affect the cost change of construction projects during the planned construction period, and this factor is greater than >: according to the cost (unit area cost or unit volume cost) of recently completed construction projects or construction projects to be completed, the influence degree of these factors on related projects (expense projects) in the project cost is predicted. Then the unit cost or total cost of the project is calculated and predicted by the specific gravity method.

In this method, firstly, the cost of similar construction projects (hereinafter referred to as reference projects) that have been completed or nearly completed recently should be calculated, including the amount of spare cost items; The second step is to analyze the factors that affect the cost, and analyze the influence degree of the forecasting factors on the cost-related projects; The third step is to calculate according to the specific gravity method and predict the cost of the current construction project (hereinafter referred to as the object project).

(b) correction of structural and architectural differences

Because of the particularity of building products, each project is different in structure and architectural design, which means that if the latest similar project cost is used as the initial forecast cost of this project, it must be revised. That is to say, we should consider two aspects: one is the structural difference between the object project and the reference project, and the other is the structural difference between the object project and the reference project.

(C) predict the factors that affect the project cost

The estimated project cost in the last step is almost impossible to be completely consistent with the actual project cost, because the project construction process is interfered by many factors, so it is necessary to analyze the influencing factors of the target project cost, determine the influence degree in the next step, and revise the estimated cost in the second step; Make it closer to the actual cost and play a role in engineering construction management.

In the process of project construction, the main factors affecting the project cost can be summarized as the following aspects:

1. Material consumption quota increases or decreases, including fuel and power.

Due to the replacement of new materials or materials, the material consumption is reduced, or the necessary process loss is reduced by the adoption of new technologies or new equipment, and the comprehensive impact caused by the difference between consumption quota and unit price when the material grade of the object project is different from that of similar projects.

2. Price rise or fall

One of the most important factors affecting the change of project cost is the change of price. The cost overruns of some projects are mainly due to the sharp price increase, which often leads to project losses, so as to fix lump sum contract.

3. The growth of labor wages

Increased labor wages (including bonuses and additional wages, etc.). ) will inevitably increase the cost of the project "including overtime j caused by tight construction period."

4. Changes in labor productivity

With the improvement of workers' quality or the adoption of new technology, the labor productivity is improved and the total construction hours are saved, thus reducing the labor cost; On the other hand, it may be due to the influence of the geographical and climatic environment where the project is located, or the quality of the construction team workers is lower than that of similar projects, which reduces the labor productivity and thus increases the total construction hours and labor costs.

5. Changes in other direct costs

Other direct costs include secondary material handling fees, temporary facilities fees, production tools and appliances use fees, inspection and test fees, engineering positioning and retest fees, engineering site fees and site cleaning fees. These costs are different for different projects. When forecasting the cost, it should be corrected according to the difference of other direct costs between the target project and the reference project on the basis of calculation.

6. Changes in indirect costs

Indirect cost is the total R&D cost of the project manager and various functional departments of the enterprise on this construction project. These costs, like other direct costs, will vary from project to project. If the scale of the project is different, the number of managers on the construction project is also different, and the salary, bonus and employee welfare expenses of managers are also different.

These factors may not all occur in specific projects, and different projects will not be the same. For example, in one period, the price of materials will rise, while in another period, the price of materials will fall. For these two projects in different periods, the cost will be reversed due to the change of material prices. Therefore, before determining the influence degree of the factors that affect the cost, we must first analyze and predict which factors affect the project.

Qualitative forecasting method is mainly used to predict the factors that affect the cost, that is, to convene relevant professionals and adopt expert meeting method. First, participants put forward their own opinions, then discuss different opinions, and finally determine the main factors (see section II).

(4) Predict the influence degree of influencing factors.

Predicting the influence degree of each factor is to predict the change of standby factors, and then calculate their influence results on related projects in the cost.

1. Predict the changes of various factors.

The choice of forecasting method of each factor change can be decided according to the nature of each factor, historical engineering data and timeliness requirements. Generally speaking, the forecasting methods applicable to each factor are as follows:

(1) empirical estimation method and time series analysis method are suitable for the change of material consumption quota;

(2) Time series analysis, regression analysis and expert survey are applicable to the price changes of materials;

(3) Time series analysis and expert investigation are applicable to the changes of employees' wages;

(4) Time series analysis and empirical estimation methods are suitable for the changes of labor productivity;

(5) Other direct cost changes need empirical estimation and statistical inference;

(6) There are empirical estimation and regression prediction for the change of indirect cost.

2. Calculate the influence degree of each factor on the cost, and calculate the influence degree of each factor on the cost with formulas respectively.

(1) Calculate the proportion of the cost components in the cost.

The calculation method is as follows: first, the cost composition ratio of reference projects is adopted, and second, the cost composition ratio of similar projects in history is used for statistical average.

(2) Calculate the influence degree of the main factors on the cost.

(5) Calculate the forecast cost.