I must not be understanding EAC properly... I thought EAC was the estimate of the final cost. Can anyone clarify why B is incorrect? SPI is sometimes used with CPI to forecast _____. A) Schedule and cost variance B) EAC C) Final project completion estimates D) What additional resources are required to get the project back on schedule Correct: C Explanation: Schedule performance index (SPI) is sometimes used in conjunction with cost performance index (CPI) to forecast the final project completion estimates.