method for calculation of BCWPS and BCWP could be used as bellow:
ܤܥܹܵ ൌ ܥ ൈ ܲ ሺͳሻ
ୀଵ
brief relationships between those equations are shown in Table 1 below:
Table 1: Standard EVM definitions and equations
ܤܥܹܲ ൌ ܥ ൈ ܲᇱ ሺʹሻ
ୀଵ
Ci is the baseline cost and Pi is planed percent completed and P’i is actual percent completed of ith activity in a project which have n activities. First for the calculation of EAC, it is necessary to introduce 2 indexes called Cost Performance Index (CPI) and Schedule Performance Index (SPI) as follows:
ܤܥܹܲ
ܵܲܫ ൌ ܤܥܹܵ ሺ͵ሻ
These values can best be understood graphically, as shown in Figure 1.
ܵܲܫ ൌ
ܣܥܹܲ
ܤܥܹܲ
ሺͶሻ
If SPI equals 1 the project would be completed on planned time; if it were less than 1 the project would be completed more than planned time; if it were more than 1, the situation would be in the opposite. In similar way, it could be forecasted the cost of project by using CPI. Various states of SPI and CPI could be seen in Figure 2 [1]. For the calculation of EAC for the project cost the following equations are generally used:
Figure 1: Earned Value
C. Literature Review of EV and EVM
ܧܣܥ ൌ ܣܥܹܲ
ܹݎ݇ݎ݁݉ܽ݅݊݅݊݃ ܥܲܫ
EV has been called the Budgeted Cost of the
Work Performed (BCWP), and it is introduced in
ൌ ܣܥܹܲ
ܤܣܥ െ ܤܥܹܲ
ܥܲܫ ሺͷሻ
ܧܶܥ ൌ ݁ݏݐ݅݉ܽݐ݁݀ ܿݏݐ ݐ ݈ܿ݉݁ݐ݁ ݎ݁݉ܽ݅݊݅݊݃ ݓݎ݇
ܤܣܥ ൌ ܶݐ݈ܽ ܾܽ݀݃݁ݐ ݂ ܾܽݏ݈݁݅݊݁
ܶܥܲܫ ൌ ିா ሺሻ
ି
ܶܥܲܫ ൌ ܶ ܥ݈݉݁ݐ݁ ܲ݁ݎ݂ݎ݉ܽ݊ܿ݁ ܫ݊݀݁ݔ
Also, EAC for time of project could be calculated by using SPI. In the equation 5 if it were used CPI×SPI instead of CPI, the worst estimation of EAC would be resulted. It could be employed a combination of SPI and CPI like A×SPI+B×CPI for EAC estimation where A and B are constant value. It is obvious that the results would be changed in each case. Moreover, it is tried to find a proper function to forecast the time and cost of a project using simulation method. In