There are three indexes that are used, to track the success of construction projects: the Schedule Performance Index, the index of price-performance ratio and the critical indices. The first is an excellent tool to use in monitoring and evaluation of your building project: the timing or performance index SPI. SPI measures the success of the project or the amount of work is completed on time. SPI is defined as the ratio between the estimated cost of work performed expressed (BCWP) to the budgeted cost of work scheduled (BCWS): SPI = BCWP / BCWS.
A project with an SPI is greater than 1.0 indicates that the project earlier than planned. If the proposed SPI is less than 1.0, the project has been delayed. An SPI equal to 1.0 indicates that the project is exactly the system – a rare event.
A consistently high value for SPI is not really a good thing. This suggests that either the timetable for the project or the budget was unrealistic. Similarly, a low and stable SPI value is not desirable. This suggests that were the original budget and timetable is too low and that insufficient time was allowed to complete the project. Using SPI as a trend barometer. If you manage a large number of similar projects, the SPI should approach 1.0 as you become more experienced with them and we learned the lessons learned from previous projects.
If the Schedule Performance Index, consider the following:
- The SPI covers all tasks, both critical and uncritical
- SPI ignores the tasks that have $ 0 budget, such as quotations, registration required
- The SPI is used in conjunction with network analysis
- Not in the SPI considered if the critical path of a project is on schedule
critical path in project management is a term used to refer to the “path” of the project on activities in addition to the longest total duration. This path is “critical” because of all the tasks that must be done on the hour or the project will be completed in time.
SPI is typically used in conjunction with the Project Cost Performance Index, CPI. The CPI measures the relationship between the budgeted cost of work performed (BCWP) and the actual work performed (ACWP) as the ratio: CPI = BCWP / ACWP.
A project with aCPIgreater 1.0 means that the actual cost is lower than expected costs or that the project under budget. A CPI less than 1.0 indicates that the project exceeds the budget. As with SPI consistently high or low values of the CPI shows that the assumptions should be reviewed.
Finally, to compare the timing and cost of performance indices for the other critical indices (CR): CR = SPI x-values should be determined for CR CPI.Charted randomly fall on either side of 1.0. Like the other two indicators to assess trends in the CR to ensure that its value remains within the predetermined acceptable range. Taken together, the performances of the schedule, cost and performance ratio of the critical indices wonderful management tools to ensure that your projects are on track and stay there.
