What is the reason that the schedule performance index (SPI) is shown as a ratio?

SPI is shown as a ratio

SPI is shown as a ratio The reason that the schedule performance index (SPI) is shown as a ratio is to—   a. Enable a detailed analysis of the schedule regardless of the value of the schedule variance  b. Distinguish between critical path and noncritical path work packages  c. Provide the ability to show performance for a specified time period for trend analysis  d. Measure the actual time to complete the project  Answer: c. Provide the ability to show performance for a specified time period for trend analysis  SPI and CPI reason shown as ratio Because schedule performance index (SPI) and cost performance index (CPI) are expressed as ratios, they can be used to show performance for a specific time period or trends over a long-time horizon. [Monitoring and Controlling]

The reason that the schedule performance index (SPI) is shown as a ratio is to— 

a. Enable a detailed analysis of the schedule regardless of the value of the schedule variance 
b. Distinguish between critical path and noncritical path work packages 
c. Provide the ability to show performance for a specified time period for trend analysis 
d. Measure the actual time to complete the project

Answer: c. Provide the ability to show performance for a specified time period for trend analysis 

SPI and CPI reason shown as ratio

Because schedule performance index (SPI) and cost performance index (CPI) are expressed as ratios, they can be used to show performance for a specific time period or trends over a long-time horizon. [Monitoring and Controlling]