Hi, I wanted to share how I quickly learned a formula dump to remember estimate at completion and estimate to complete and an easy way to understand when to use one or the other with the given information.

·         FIRST write down EAC four times

·         Then write down ETC three times

·         With smaller letters..spell out RATS and RAT

·         Practice memorizing the order of formulas many times

·         Practice writing it down more

·         Then understand why we use one or the other

EACR                    AC+ETC                                                                            Flawed estimate the “R” means Rebase line

EACA                    AC+ (BAC-EV)                                                                   “Atypical” estimate at budgeted rate

EACT                    BAC/CPI                                                              “Typical” no variances in future

EACS                    AC+ ((BAC-EV)/ (CPI*SPI))                             meet “Schedule” or deadline             

ETCR                     EAC-AC                                                           “Recommended” when no other info is given    

ETCA                    BAC-EV                                                               “Atypical” variances detected

ETCT                     (BAC-EV)/CPI                                                    “Typical” assuming no variances in future