This document contains formulas for calculating present value, future value, expected duration using PERT analysis, variance and standard deviation for activities, earned value techniques like cost variance, schedule variance, estimated cost at completion, and formulas for calculating slack, communication channels, and point of total assumption.

1. Formulas
Present Value PV=FV/(1+r)^n
OR
FV=PV(1+r)^n
Higher is better.
FV= Future Value,
R= interest rate,
n= no. of time periods
PERT (Program Evaluation and Review Technique):
Title Formula Notes
3 Point estimate –Beta
distribution
Expected
duration=(P+4M+O)/6
P: Pessimistic
M: Most Likely
O: Optimistic3 point estimate- Triangular
distribution
Expected duration=
(P+M+O)/3
Standard deviation of an activity
(SD)
(P-O)/6
Variance of an activity (SD)^2
Standard deviation of the
project
Sqroot(Sum of all activity
variances)
Earned Value Techniques:
Title Formula Notes
Cost Variance (CV) CV = EV – AC Minus is over budget
Schedule Variance (SV) SV = EV – PV Minus is behind
schedule
Est. At Completion (EAC) EAC = BAC/CPI Same rate of spending
EAC = AC + Bottom
up
Use when Initial
Estimates are flawed
and no longer valid
EAC = AC + (BAC-EV) Use when future
variances are atypical
EAC = AC + [(BAC-
EV)/CPI*SPI]
Considering SPI and CPI
which influences
remaining work
Est. To Complete (ETC) ETC = EAC – AC

2. Var. At Completion (VAC) VAC = BAC – EAC
Schedule Performance Index
(SPI)
SPI = EV / PV Less than 1 is behind
schedule
Cost performance index (CPI) CPI = EV / AC Less than 1 is over
budget
To Complete Performance Index
(TCPI)
TCPI = ( BAC - EV ) /
( BAC - AC )
For Managing to
budget. Values for the
TCPI index of less than
1.0 is good because it
indicates the efficiency
to complete as less than
planned. How efficient
must the project team
be to complete the
remaining work with the
remaining money.
TCPI = ( BAC - EV ) /
( EAC - AC )
For managing to
specified value(EAC)
Calculating Slack or Float:
Title Formula Notes
Total Float LS – ES
Or
LF-EF
LS=Late Start, ES= Early Start
LF=Late Finish, LS= Late Start
Communications
Title Formula
Communication Channel n(n-1)/2
Point of Total
Assumption (PTA)
((Ceiling Price - Target Price)/buyer's
ratio)+Target Cost
For the FP contract