Schedule % Complete is one of the many percent completes you have in Primavera P6 and we’re going to have a complete look at what it is and how it is calculated. Two important products of maintaining schedules are planned progress and actual progress of a given time; you want to know how much you’ve done so far and compare it with how much you were supposed to do so far, in order to reach project targets.
The first thing to mention is that Schedule % Complete deals with planned progress. As a result, it is calculated based on the Project Baseline and the Data Date; it has nothing to do with the current schedule.
The second thing is that this field is calculated differently for Activities than for WBS Elements. This is the source of the most common problems people have with this field.
Schedule % Complete for Activities
And now, let’s start the story with how Schedule % Complete is calculated for Activities. It’s simple; just take a look at the following figure.
When the Data Date is earlier than the Baseline Start date, Schedule % Complete is zero, when it’s after the Baseline Finish data, Schedule % Complete is 100%. Otherwise, Schedule % Complete would show what percentage of the Baseline duration is passed by the Data Date. Here’s a formula to calculate Activity Schedule % Complete:
Schedule % Complete(Act) = ( [Data Date] – [Baseline Start] ) / ( [Baseline Finish] – [Baseline Start] )
The following diagram shows the Schedule % Complete of a single Activity for different Data Dates:
And that’s all for the activities; it has nothing to do with the current schedule, the resource curves, the costs, etc. For Activities, Schedule % Complete is strictly calculated based on:
- Data Date
- Activity’s Baseline Start
- Activity’s Baseline Finish
Schedule % Complete for WBS Elements
And now, the story of how Schedule % Complete is calculated for WBS Elements. Let’s start by reviewing 2 possible scenarios:
How are these calculations possible? The Sample WBS Element has three Activities, they all have Schedule % Completes greater than zero, but the value for Sample WBS Element is 0! Before I reveal the answer, here’s a contrasting scenario.
In this scenario, the Sample WBS Element has three Activities with Schedule % Completes less than 50%, but the Schedule % Complete of the WBS Element is 75%.
What is going on here? How is Schedule % Complete calculated in each scenario?
A WBS Element’s Schedule % Complete is calculated in a completely different way. You might expect it to be the rollup value of the underlying Activities (a weighted average for example). But, as in scenario 2, the three Activity values which are all less than 50% could never have a weighted average more than 50%.
As you saw before, the Schedule % Complete of the Activities is time-based. However Schedule % Complete for WBS Elements is:
- Depended project costs and…
- Does not factor in any Activities’ Schedule % Complete values
How Schedule % Complete is Calculated for WBS Elements
When you assign resources and expenses to activities, each activity will receive a calculated Total Cost. Resource assignment hours and costs are, by default, spread uniformly over the duration of the activity (but you may apply a Resource Curve to alter this). Oracle Primavera will show you how costs are then planned for each day of the Activity. These costs are aggregated to the WBS level, and the time-phased cost of the WBS Element will be calculated automatically.
The Schedule % Complete of the WBS Element will be the ratio of the Baseline Costs before the Data Date to the Total Baseline Cost.
In the world of Earned Value, the costs before the Data Date are called the Planned Value, or PV for short (Also called BCWS – Budgeted Cost of Work Scheduled). The total baseline cost is called Budget At Completion or BAC for short. We can now formulate the calculation of Schedule % Complete for WBS Elements as:
Schedule % Completed (WBS) = PV / BAC
Please have this in mind that all the mentioned parameters are derived from baseline and not from current schedule; the WBS bar shown in these figures is the baseline schedule of the WBS Element and the costs are the baseline costs of the WBS Element.
The following diagram shows Schedule % Complete of a sample WBS Element for different Data Dates:
The above descriptions show that the Schedule % Complete of the WBS Elements depend on the following:
- Data Date
- Baseline Costs before the Data Date (PV)
- Total Baseline Costs (BAC)
To summarize, Schedule % Complete for Activities is based on time, while its value for WBS Elements is based on costs.
Pulling Schedule % Complete together for WBS and Activities
The following diagram shows Schedule % Complete of a sample WBS Element with two Activities in different Data Dates.
In Part 2 of the Schedule % Complete Guide, I’ll show you an example of using Schedule % Complete on a project in P6.