indicated in the figure above, there are two scenarios for using TCPI, each
scenario requiring a slight deviation in the calculation.
first scenario employs a TCPI based on the authorized budget, i.e. Budget at
Completion. This is used to determine the required performance based on what
has been authorized in the form of an official budget. Once it becomes obvious
that the budget (or performance) is no longer achievable, the project
management team needs to determine how much money it will cost to complete work (called
the EACc). It is not uncommon for projects, when making a new EAC forecast, to
assume that everything will suddenly go right, and that all project risks are
behind them. Thus, an initial EACc may be unrealistic or unachievable.
Piecemeal EACs are often the norm, where the EACc projection goes up each month
as actual performance is known.
the above, the second scenario in using TCPI is to determine, and verify the
required future EACc. If the resulting TCPI based on the new EACc is higher or
much lower than the existing performance (CPI), it would be reasonable to
assume that the new EACc might not be accurate.
the previous example, would an EACc requiring a future TCPI of 1.25 or 1.10 be
achievable? Probably not. More likely, a TCPI of 1.0 or 0.9 would be reasonable.
EACc is assumed to be correct if the indexes are the same for both scenarios.
involves the calculation of a project’s Estimate at Completion (EAC) values.
The EAC values should represent the total project considering performance
(actual) to date, plus future estimate to completion (ETC).
EAC information with the performance measurement baseline to identify the
current variances from the plan, important to management and any applicable
customer reporting requirements.
The EAC Calculations
consist of the following forecasts to consider:
at Completion (EAC) – Bottom up.
Estimate at Completion for Cost (IEACc).
22.214.171.124 Estimate at Completion – Bottom Up
Completion using the bottom up approach (also referred to as a formal EAC),
should be based on the following:
period of the project.
a complete review of the plan to complete the project.
of the actual costs to date plus the Estimate to Complete (ETC).
at the work package and planning package level of the control account.
review of the remaining scope of work and the schedule for completing the
remaining scope of work.
all approved change control since the last EAC and considers selected identified
early warning issues.
complete re-evaluation of project risks, including technical, schedule, and
Estimate at Completion for Cost
Independent Estimate at Completion for Cost provides a statistical final cost
indication. It should only be considered as a “Reasonableness Test” and does
not replace the Bottom up EAC.
Independent Estimate at Completion (IEAC) the following three variables are
actual costs to date.
of work remaining for uncompleted tasks (BAC – EV).
of the remaining work by some performance efficiency factor, which is used to
produce a range of EACs.
should be considered when using IEAC calculations:
not be your final EAC.
be used for comparative analysis.