What is earned value? How to calculate?

Suppose that the duration of a job is 10 days, the budget cost is 100 yuan, that is, the daily completion progress is about 10%, the cost of the daily investment is about 10 yuan. Now, at the end of the fifth day, when we monitor the project, we find:
1. The work was done only 40%
2. The actual cost has been spent 60 yuan
It seems that the implementation of the project is very bad, the progress and cost of two aspects of unsatisfactory, then the current situation is how the project? So how bad is it? We use the following indicators to illustrate:
1. Earned Value (EV), the budgeted cost of work that has been completed.
Calculated as: Task Budget Cost * Percentage of jobs completed
As an example, that is: 100*40%=40 yuan
What is the cost of the budget/or the cost of the job to complete the previous work?
2. Actual Cost (AC), also known as the time cost of the completed work
No computing company is the cumulative cost of work (including all kinds of labor, materials, equipment, and other
Various fees, etc.)
As an example, that is: 60 yuan
3. Program Value (PV), also called planned work budget cost. That is to say, how much work should be done so far, and how much of that work should be budgeted.
Calculated as: Task Budget Cost * Percentage of scheduled completion jobs
As an example, that is: 100*50%=50 yuan
4.CPI, cost performance indicator, this value is a major measure of the cost implementation and control of the project
Calculation formula: BCWP/ACWP
As an example, that is: 40/60=66.67%
The implication of this indicator is that, on average, in order to complete the same work, the budget will only cost $6.667, while the actual investment is $1.
5.SPI, Progress performance indicator, this value is a major indicator of project execution and control
Calculation formula: BCWP/BCWS
As an example, that is: 40/50=80%
The meaning of this indicator is that, on average, in the same time, the task should be invested 1 yuan, and the time is because of slow work and only invest
The 0.8 yuan. Indicates that the progress is too slow.
Other indicators include the cost of the deviation cv=bcwp-acwp=40-60=-20 yuan, indicating that the first 5 days, in order to complete the same work, the cost of more than 20 yuan invested.
The calculation of the above-mentioned indicator is actually the cost execution and control performance analysis of the previous phase (5 days), then the implementation and control performance based on such cost
How much will it cost to complete the rest of the task? This job is cost prediction:
The predictions are hypothetical:
1. Assuming that the cost performance of the follow-up work will be fully budgeted, the result is:
Work remaining * Task Budget cost
As an example, that is: (1-40%) *100=60 yuan.
It also needs 60 yuan.
2. Assuming that the cost performance of the follow-up work will be carried out according to the previous performance, the result is:
(Remaining Work * task budget Cost)/CPI
The implication is, such as the former performance indicators CPI, in order to complete the same work, the budget only needs to invest 6.667 yuan, but actually invested 1 yuan.
Then, in order to complete the next 60% of the work, the budget is 60%*100=60, but based on experience, this is not enough, the actual still need to forecast costs
is 60/cpi=90 yuan.
We need 90 bucks.

As before, we saw the project cost performance analysis and cost prediction, and now my question is: what is the cost of "should"-the calculation of earned value
From the BCWP calculation, the formula is: Task Budget Cost * Percentage of jobs completed. We know that a task or homework.
is the smallest unit of the cost budget, and as to how this budget cost is invested within the job (when, how much) is no matter, the budget
Only the total amount. But we see that the calculation formula, for the job/task "should" in the cost calculation, there is a hypothesis:
The cost input is a function of the percentage of job completion, and it is a linear function. That is, how much the job is done, and how much the cost should be invested accordingly.
But we need to know that this cost is the total cost of the operation, including labor, materials and so on. And in fact, we should see the cost increase as the work progresses
Not always on a synchronous. For example, buy and install a large device. Perhaps, only 1% of the total workload of the equipment purchase cost, may account for the total cost of the job 99%.
If the purchase takes 1 days, the installation is going to be 99 days, and if you calculate the CPI for the job by the 100th day, the total is less than 1. But we can come to the conclusion
Is there a problem with the cost of doing this job?
So, when we look at the value of earned value and CPI, we can't ignore the hypothesis implied in their calculations, if we face
The actual situation is too far from the two assumptions, then these two indicators to lose the reference role, will affect the decision-making and prediction.
So, I think that in order to make this analysis as close to the right as possible, we need to analyze the project's cost execution and control performance with earned value technology.
Pay attention to this hypothesis in the earned value calculation formula, and approach this hypothesis in the organization and analysis of the actual work:
1. When the job is divided, take into account that the cost increase in the job is as linear as possible with the job completion, so as to avoid the case of my example
2. The cost performance index, which is not done correctly, is more realistic on the macro level and distorted at the micro level.

Earned value analysis notes the following points:
When the CV is positive and the SV is negative, either the task has not started or the task has started, but no sufficient resources have been allocated;
When the CV and SV are negative, the cost overruns and the progress lag is indicated;
When the CV is negative and the SV is positive, it indicates that the acceleration measures have been taken through the additional investment;
When both CV and SV are positive, the project is controlled within the budgeted cost and ahead of schedule.

What is earned value? How to calculate?