The project schedule is an invaluable tool to plan the execution of a project. It should be prepared at the beginning of the project and a baseline used as a reference for measuring performance. Completion of tasks information needs to be recorded in the schedule for two important reasons: The first is to determine performance, and the second is to revise the plan for the rest of the project.
The actual start date of the task should be recorded; there are two ways to do this:
- Direct: manually entering the actual start date of the task
- Indirect: entering % complete > 0, an actual duration or an actual finish date. In this case the start date is derived from the baseline.
Once the task has started, progress is recorded in any of the following ways:
- If the task type is fixed duration then % complete or actual duration is entered on the task.
- If the task type is fixed work then % work complete or actual work is entered for the task.
- Entering work done by individual resources allocated to the task. This is done where the actual work performed by each resource is used to measure progress. This can be labour intensive and is usually implemented with an automated interface to the timesheet system.
The cost of the work completed can be calculated by Project based on the work performed by each resource or entered manually in the actual cost field of the task. In order to enter costs manually the flag in the calculation tab of the options menu must be cleared to prevent Project from calculating cost. This is the approach used for earned value when the actual costs need to be tracked.
There are two other fields that are used to confirm the schedule for the remaining portion of the project. These are the remaining duration and the remaining work. Remaining duration should be used with fixed duration tasks, and remaining work with fixed work tasks to review the estimated time required to complete the task. The additional time or work is apportioned to the task using the existing resource allocation parameters (Units, Contour, assignment dates, etc).
These fields should be used with caution because they can change resource allocation parameters which have an effect on successor tasks on both critical path and critical chains.
If earned value is being used then changing the remaining duration or work of a task will alter the % complete or % work complete of the task, invalidating earned value history. In this situation the Physical % complete should be used and updated manually. We will address Earned Value in a future article.
Entering an actual finish date closes the task at that point and accrues only the work performed to-date. The remaining tasks are rescheduled according to task dependencies, resource allocation and constraints. If calculation and levelling are set to automatic, this will re-schedule the rest of the project and it should be analysed to ensure that the project is on track from a scheduling perspective.
An up-to-date schedule is a valuable planning tool, but tracking progress in a schedule is a bit more involved than just entering % complete. In fact there are three different % complete fields with different meanings that are used for different purposes. That is the topic of the next article.