To-Complete Performance Index (TCPI) (Project Management KPI): Formula and Example

Business context

Why To-Complete Performance Index matters

Trend To-Complete Performance Index with its numerator, denominator, or contributing inputs so that a shift in scale is not mistaken for an efficiency change.

Business question: Where does To-Complete Performance Index differ most across comparable teams, products, channels, or periods?
Teams that use it: Project managers, delivery leads, finance, operations, and project sponsors.
Decisions it supports: Schedule recovery, budget control, scope choices, staffing, and delivery-risk management.

Calculation

To-Complete Performance Index formula

(Planned Budget - EV) ÷ (Planned Budget - Actual Costs)

Formula components

Planned Budget: The monetary amount assigned to planned budget for the same scope and reporting period used by To-Complete Performance Index.
Actual Costs: The monetary amount assigned to actual costs for the same scope and reporting period used by To-Complete Performance Index.
Reporting period: The consistent day, week, month, quarter, or year covered by every input.

How to calculate To-Complete Performance Index

Define the business scope, reporting period, and the event or status that qualifies for To-Complete Performance Index.
Remove duplicates and exclusions according to the documented rule, while retaining a reconciliation count.
Collect each input in the workbook formula from systems that use the same cut-off and unit.
Apply (Planned Budget - EV) ÷ (Planned Budget - Actual Costs) and label the result with its period, unit, and relevant segment.

Worked example

To-Complete Performance Index example

A fictional team uses one scope and period for every To-Complete Performance Index input.

Planned Budget = £120,000; Actual Costs = £60,000.
Planned Budget = £120,000.
To-Complete Performance Index = (£120,000 − £60,000) ÷ £120,000 = £0.5.

To-Complete Performance Index is £0.5.

The calculation preserves the workbook order: first take the difference, then divide by the stated comparison base.

How to interpret the result

Compare To-Complete Performance Index over a consistent cadence and break it down only by segments large enough to support a decision. Review the formula inputs beside the result so teams can distinguish a real operating shift from a denominator or mix effect.

There is no single target that fits every organisation. Interpretation depends on project type, delivery method, scope, complexity, team capacity, and reporting date. Document the comparison group before labelling a result strong or weak.

Common mistakes and limitations

Inconsistent scope: Changing the included business units, products, channels, or populations makes the trend look different even when underlying performance is unchanged.
Mismatched periods: Formula inputs from different cut-off dates or time windows do not describe one coherent result.
Ignoring response and scoring bias: Changes in who responded, how the question was presented, or how weights were applied can move the score without an equivalent experience change.
Assuming one universal target: A useful comparison depends on project type, delivery method, scope, complexity, team capacity, and reporting date; use like-for-like internal trends and clearly documented peer groups.