Schedule Performance Index (SPI) describes how efficiently we are actually progressing compared to the planned project schedule. The Schedule Performance Index (SPI) can be defined as a measure of schedule efficiency expressed as the ratio of earned value to planned value.
The Schedule Performance Index gives the information about the schedule performance of the project. It is the efficiency of the time utilized on the project.
Calculation of Schedule Performance Index (CPI):
The Schedule Performance Index can be computed by dividing earned value by planned value.
SPI = EV / PV
Earned Value (EV): Earned Value is the amount of the task that is actually completed. Planned Value (PV) = Planned Completion * Task Budget
Interpretation of SPI:
- SPI > 1:
If the SPI is greater than one then more work has been completed than the planned work. In other words we can say that project is ahead of schedule.
- SPI < 1:
If the SPI is less than one then less work has been completed than the planned work. In other words we can say that project is behind schedule.
- SPI = 1:
If the SPI is equal to one then work is being completed at about the same rate as planned. In other words we can say that project is on time.
Given a project to be completed in 12 months and the budget of the project is 1, 00, 000 INR. Six months have passed and 60, 000 INR has been spent but on closer review it is found that only 40% of the work has been completed till now.
Find the Schedule Performance Index and conclude whether the project is behind or ahead of schedule.
Actual Cost (AC) = 60, 000 INR
Planned Value (PV) = 50% of 1, 00, 000 INR = 50, 000 INR
Earned Value (EV) = 40% of 1, 00, 000 INR = 40, 000 INR
SPI = Earned Value / Planned Value = 40, 000 / 50, 000 = 0.8
Hence, the Schedule Performance Index is 0.8.
Conclusion is that the project is behind schedule since the Schedule Performance Index is less than one.
Attention reader! Don’t stop learning now. Get hold of all the important CS Theory concepts for SDE interviews with the CS Theory Course at a student-friendly price and become industry ready.
- Difference between Cost Performance Index (CPI) and Schedule Performance Index (SPI)
- Software Engineering | Cost Performance Index (CPI)
- Software Engineering | Cost Variance (CV) and Schedule Variance (SV)
- Software Engineering | Introduction to Software Engineering
- Software Engineering | Requirements Engineering Process
- Software Engineering | Re-engineering
- Software Engineering | Reverse Engineering
- Difference between Software Engineering process and Conventional Engineering Processs
- Performance Testing | Software Testing
- Difference between Cost Variance and Schedule Variance
- Cost and Schedule Estimating Process
- Difference between Forward Engineering and Reverse Engineering
- Difference between Performance and Stress Testing
- Difference between Performance Testing and Load Testing
- Software Engineering | Halstead’s Software Metrics
- Software Engineering | Classification of Software Requirements
- Software Engineering | Classification of Software
- Software Engineering | Software Project Management Complexities
- Software Engineering | Role and Responsibilities of a software Project Manager
- Software Engineering | Seven Principles of software testing
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to firstname.lastname@example.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.