What does a CPI or SPI value less than one indicate about a project?

A Cost Performance Index (CPI) or Schedule Performance Index (SPI) value less than one indicates that a project is over budget or behind schedule. In project management, these indices are critical for assessing project health.

For CPI, a value less than one means that the amount spent on the project exceeds the value of the work performed, suggesting cost overruns. Similarly, for SPI, a value under one indicates that the project is behind schedule, meaning that less work has been completed than was planned at the same point in time. Therefore, having either of these indices below one serves as an early warning sign that corrective actions may be necessary to get the project back on track with respect to budget and timing.

The other choices reflect scenarios that do not align with the definitions of CPI and SPI, such as being on budget or schedule or having all tasks completed, which would not apply when the indices are below one.