Project success indicators focusing on residential projects: Are schedule performance index and cost performance index accurate measures in earned value?

Abstract

As a concept of project control that provides a quantitative measure of schedule and cost information, earned value (EV) can evaluate work progress by identifying potential delays and cost overruns. When EV is used as a construction control technique, the schedule performance index (SPI) and the cost performance index (CPI) are the core factors in the EV system. The standard is only 1, i.e., 1.0 above or below. Though the two indices have important roles in the EV system, those indices do always show the project status exactly; for example, when planned value (PV), EV, and actual cost (AC) are not collected in a timely manner. Additionally, there is no guideline on how each value in SPI and CPI is understood or how to read the hidden meaning behind the construction status. Therefore, this study first speculates about the meaning of the two indices, then suggests a practical application, and finally shows the framework where the two indices apply to various types of construction.