When your P6 Professional schedule is cost-loaded, the performance % complete metric provides a robust, accurate assessment of project progress.
When a schedule has no costs (unloaded) or is loaded only with zero-dollar resources (e.g., man-hours), P6 Professional offers three activity % complete types to measure progress: Duration %, Physical %, and Units %. We discuss how to decide which type to choose for your schedule progress situation in the following article.
But when cost-loaded, however, a fourth measure becomes available, performance % complete. This measure is used in Earned Value (EV) calculations. It is based on the selected percent-complete technique: duration %, units %, physical %, or another technique (e.g., 0/100 or 50/50) for computing performance %. And the resulting EV value rolls up from tasks to WBS elements.
This article differentiates performance % from P6 Professional’s three activity % complete progress metrics: duration %, physical %, and units %.
Project Measurements
Let’s examine each activity: % complete, duration %, physical %, and units %, which are valid for both non-cost-loaded and cost-loaded schedules. Then we will discuss performance % for cost-loaded projects. Before studying the measurement metrics, it would be helpful to review how to progress a schedule. Refer to the following article for a primer on progressing a schedule in P6 Professional.
Duration %
Regardless of the schedule’s cost-loading situation: no-loading, resource-loading, or cost loading, duration % is useful. Duration % simply measures the passage of time on a project that may or may not align with achievement. And it is considered the “Time” metric because it assesses progress based on the time spent on a schedule. P6 Professional takes this time passage (duration %) and original duration (OD) to compute the remaining duration (RD) of each task using the following equation:
Reorganizing this equation for when we do not know the duration %, we can calculate it from the following:
One advantage of duration % is that P6 Professional calculates it at the WBS element, using the same reorganized duration % equation. As duration % requires limited input, it is an efficient way to describe schedule progress. But it is the least accurate way to define progress because it assumes a uniform production rate, which is often unrealistic.
However, if your foreman or project manager cannot obtain an accurate assessment of achievement or a revised RD, you will be better served using the linear (production rate) and efficient duration % metric.
Physical %
Physical % is a measure of achievement and is the “judgment” metric: the foreman visually inspects work and assesses accomplishment as of the data date (DD), i.e., the status date. Additionally, it separates this achievement from specified estimates of remaining work (revised RD estimate or an expected finish date), enabling you to model non-uniform production rates. For example, the accomplishment of the first 50% requires two days of work, but the remaining 50% only takes you one day, or less time.
This percent-complete type is considered more accurate than duration %, but note that it is only as accurate as the estimator’s (or foreman’s) judgment call, a slight caveat. Because physical % is an appraisal metric based on expert opinion (achievement and revised RD estimates), P6 does not presume to compute physical % at the WBS level; it calculates only at the task level.
Units %
Units % tracks effort expended or work. This “work” metric requires a resource-loaded schedule, but only for man-hours; pay rate can be excluded. For the units %, in addition to providing a units %, the scheduler specifies the actual labor units for each resource assigned to the task.
This metric is useful to capture multiple resources working at different effort rates. And it results in a very accurate assessment of effort, but like physical %, you must enter a revised RD or expected finish date. Units % is calculated at the task and WBS level. It is also referred to as the “burn” metric because it primarily measures hours spent. Units % is calculated using the following formula:
P6 Professional computes units % at the tasks and WBS levels.
Performance %
When your schedule is fully cost-loaded (resource-loaded for man-hours and salary), you have the data necessary to translate field updates into financial metrics. At the activity level, Performance % mirrors the task’s assigned Percent Complete Type discussed above, where:
- Duration % is the least accurate, as it measures the passage of time rather than work performed.
- Units % provides a precise measure of “effort exerted” (man-hours).
- Physical % is the preferred type; it reflects actual deliverables earned and is the most conservative, as it is often easier to claim “effort exerted” than “deliverable accomplished.”
At the task level, Performance % Complete serves as the operational/field progress measure. P6 computes the EV from this input:
The EV of each task then rolls up to the WBS level, where performance % is calculated as:
So, at the task level, Performance % is an operational metric representing Field Progress. At the WBS level, it transforms into a financial metric representing Value Realized.
Demonstration – Performance %
For the conservative physical % (activity % complete technique), we investigate performance % across scenarios: constant vs. varying expenditures, and cases where physical % equals or differs from duration %. Displayed in Figure 1, is our demonstration project.
This schedule has a five-day, eight-hour workweek. It is a lump-sum cost-loaded schedule, with a baseline established prior to progress. And it has progressed for two weeks. We investigate the progress of the Piping WBS element and underlying tasks.
Expenditures Constant
When daily expenditures are constant (Time = Money), performance % becomes mathematically equivalent to duration-weighted task physical %:
For our piping deliverable, Figure 2, so far, only Install Piping & Couplings has progressed to 66.66%, with physical % equaling duration %.
The performance % at the Piping WBS level is then the duration-weighted average of task progress values calculated as follows:
This exactly matches the EV/BAC calculation:
Thus, for constant expenditures with physical % equal to duration %, duration-weighting equals performance %, as measured by EV metrics.
Expenditures Constant – Physical % Manual Input
When expenditure is constant and physical % does not equal duration %, as follows:
The performance % cost-weighted equation again collapses to a straight duration-weighting of tasks, where Time = Money. The performance % for an individual task is as follows:
When the physical % Install Piping & Couplings is specified at 50%, the performance % is 50%, as shown in Figure 3.
At the Piping WBS level, the duration-weighted average task progress is calculated as follows:
This result is mathematically identical to the standard EV and BAC formula:
For constant expenditures, even when physical % differs from duration %, task duration-weighting remains perfectly aligned with EV performance %.
Expenditures Differ
When resource costs vary across tasks, performance % uses cost-weighting: In Figure 4, only the Install Piping & Couplings shows progress, where physical % equals duration %.
And note that the Install Piping & Couplings task’s $9,600, the Test Piping at Pressure task’s $800, and the Insulate Piping task’s $3,200 costs are not linearly dependent on duration. The cost-weighted average of Piping tasks is:
The WBS-level EV performance % confirms:
This confirms that when expenditures differ, physical % equals duration %, activity-level cost-weighting equals WBS-level EV metrics.
Expenditures Differ – Physical % Manual Input
IWhen expenditures vary and Physical % ≠ Duration % (manual input):
In Figure 5, Install Piping & Couplings is set to 50% physical %, yielding identical 50% performance % at the task level.
Because the task costs are duration-independent, the Piping WBS calculates overall progress from weighted manual inputs:
The corresponding EV/BAC equation yields the same result:
Even with non-linear cost distributions and manual physical % inputs, task cost-weighting remains mathematically synchronized with the EV performance %.
Summary
The attributes of each percent complete type are summarized in Table 1.
Table 1 – Percent Complete and Attributes
| Percent Complete Type | Metric | Usage | Loading Requirement | ProductionRate | ResourceAssignment Burn** | ComputedAt |
| Duration % | Time | Time-Driven | None | linear | Uniform | Task/WBS |
| Physical % | Judgement | Deliverable-Driven | None | linear/non-linear | Uniform | Task |
| Units % | Effort | Resource-Driven | Resource-Loaded | linear/non-linear | Can Differ | Task/WBS |
**” Resource Assignment Burn: Equal” – Multiple resource assignments on a task consume at the same rate/expenditure.
“Can Differ” – Individual resource assignments can be consumed at different rates.
Duration % is the most efficient to enter, but the least accurate. It has a linear correlation to the remaining duration (RD) or the expected finish date. Ideal for complex research where an accurate assessment of achievement is unavailable.
Physical % relies on expert judgement and is best for tasks where the work is not at a steady pace (nonlinear); it separates achievement from a revised remaining duration (or expected finish date).
Units % tracks man-hours (not pay rates), measuring effort expended rather than deliverables accomplished. Its advantage is that its resource assignment burn rates can vary, enabling a very accurate assessment of effort expended.
Following the comparison of activity % complete progress types, Table 2 outlines the performance % attributes for EV management.
Table 2 – Performance % and Attributes
| Level | Metric | Usage | Source of Progress | Weighting Method |
| Task | EV | Operational | Physical % | Direct |
| WBS | EV | Financial | Task EV Rollup | Cost (EV/BAC) |
Performance % serves as a dual-purpose variable, bridging operational (task-level) and financial (WBS-level EV/BAC or cost-weighted average) metrics. This ensures project progress is driven by financial weight (BAC) rather than a simple count of completed tasks. While it requires cost-loading, it enables high-level EV metrics across the WBS, unlike physical %, which only computes at the task level.
The WBS performance % computations are further detailed in Table 3, where the WBS EV technique is set to “Activity Percent Complete,” and tasks are assigned the physical %.
Table 3 – WBS Performance % Computations
| Scenario Number | WBS EV Technique Activity % Complete | Expenditures | Task Physical % Vs. Duration % | Task Average Method | Task Weighted Average = EV/BAC |
| 1 | Physical % | Constant | = Duration % | Duration-Weighted | ✓ Equals |
| 2 | Physical % | Constant | ≠ Duration % | Duration-Weighted | ✓ Equals |
| 3 | Physical % | Differ | = Duration % | Cost-Weighted | ✓ Equals |
| 4 | Physical % | Differ | ≠ Duration % | Cost-Weighted | ✓ Equals |
When the WBS Earned Value Technique is set to physical % (activity % complete), two key insights from our performance % computations follow.
- Constant expenditures: duration-weighted averaging perfectly matches EV/BAC rollups.
- Varying expenditures: cost-weighted averaging is required to align with true EV/BAC rollups.
This explains why WBS performance % mirrors simple task averages in linear projects but diverges in complex schedules with non-linear resource costs.
Our demonstrations show that EV/BAC = task-weighted averages by duration or cost, confirming performance % is rigorously consistent across operational and financial views. When paired with physical %, it reflects actual deliverable achievement, producing conservative, achievement-oriented, and mathematically perfect WBS rollups.
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