# Typical vs Atypical in EV

Typical - No variances. No variances will occur in the FUTURE. BAC/CPI(cumu)

Atypical - Variances has occured but will not occur in the FUTURE. AC + (BAC - EV)cO

Please correct me if my interpretation is wrong.

### I presume the left hand side

I presume the left hand side of your formula equations to be   'EAC = '.  Am I right?

What is the 'cO' to the very end in your second formula?

### Re

Yes EAC. Co is some typo.

### Concept

We shall try to understand the meaning of typical & atypical.

Typical - Some variances have occured and it is expected to continue in future too.

Atypical - Some variances have occured and it is not expected to continue in future.

Formulae:

EAC ‘fundamentally flawed’ = AC + ETC

EAC ‘Typical’ = BAC / CPI

EAC ‘atypical’ = AC + (BAC – EV)

EAC considering both CPI & SPI = AC + [(BAC-EV)/(CPI*SPI)]

### true and agree to it

true and agree to it completely.

### AP,As per the Abhi and

AP,

As per the Abhi and Rajesh Nair cheat sheet, i could see the following formulas. For typical and atypical it is different thant what you said. Please clarify my doubts

CV = EV - AC

CPI = EV / AC

SV = EV - PV

SPI = EV / PV

EAC ‘no variances’ = BAC / CPI

EAC ‘fundamentally flawed’ = AC + ETC

EAC ‘atypical’ = AC + BAC - EV

EAC ‘typical’ = AC + ((BAC - EV) / CPI)

ETC = EAC - AC

ETC ‘atypical’ = BAC - EV

ETC ‘typical’ = (BAC - EV) / CPI

ETC ‘flawed’ = new estimate

Percent Complete = EV / BAC * 100

VAC = BAC - EAC

EV = % complete * BAC

Formula for TCPI to meet the BAC is: TCPI = (BAC-EV) / (BAC-AC)

Formula for TCPI to meet the EAC is: TCPI = (BAC – EV) / (EAC – AC)

### Hi

EAC = AC + (BAC-EV)/CPI is the formula that was given in PMBOK guide third edition.

In fourth edition, the same formula is simplified to EAC = BAC / CPI. Both the formulae are correct.

Kindly refer this url which clearly derives the equation.

http://www.deepfriedbrainproject.com/2010/01/solving-estimate-at-completion-puzzle.html

### For everyone who has to yet

For everyone who has to yet give PMP Exam, Please remember all the formulas. I had so many mathematical questions in the exam and not all are straightforward. Understanding EAC and ETC is very important for exam