PM Foundations – Managing Schedule Performance
August 7, 2011 Leave a comment
Project success is highly dependent on understanding actual progress compared to planned progress, and making the appropriate adjustments throughout project execution. Based upon my experience, the project schedule represents the single most important source of information to assess and manage project performance. The project schedule provides information related timing, work effort, and resource utilization – all important elements of identifying variances, performing root cause analysis, and implementing corrective actions.
Assessing Schedule Performance
Effectively managing schedule performance starts with performing regular analysis of the schedule to identify potential problems or opportunities in the schedule. Begin the analysis at a high level by looking at key summary tasks and milestones.
Look for areas that the planned dates are not tracking with the baseline dates:
- Finish variances indicate tasks or milestones that will either complete early or late.
- Start variance indicate tasks or milestones that will either start early or late.
In addition, examine the % Complete:
- Do you have gaps between the duration that is completed and the work that has been completed? These gaps point to areas where progress is largely tied to non-resourced tasks, and “real work” may be “hidden” by this progress.
- Do you think it is reasonable to complete the remaining work in the days remaining for the task (or series of tasks)? To answer this question, you may need to take a closer look at the detailed tasks below the summary task, or the tasks tied to the milestone.
Performing Root Cause Analysis
Once you have identified that a summary task or milestone is potentially slipping, you must identify the source of the potential problems. Look deeper into the schedule to identify the task or group of tasks that are driving the variance.
Examine the tasks to determine the specific cause of the variance:
- The duration was adjusted, moving the end date out (likely because the task is late getting started).
- The work effort and duration were adjusted, moving the end date out (likely because the effort is greater than planned).
- The end date for a dependent task moved, impacting this task.
- New tasks were inserted into the schedule that this task is now dependent upon.
Generally, the next step in the process is to talk to team members to find out the reason these changes were made. Many times you, as the project manager, were the one that made the change so you already know the answer to these questions. Look for the “rest of the story” associated with this variance:
- Why is the task late getting started or finished? Is it related to resources? Resources have not been available to start/finish the task, or the resources are struggling with the tasks?
- The work effort has turned out to be greater than originally planned. Is this because scope has been added, or potentially with more information (clarification) it has turned out to be something different than first planned?
- Are there open issues associated with the task that are preventing progress (the task is “stuck” awaiting resolution of issues). The issue tracking log is a good source of information for this type of problem.
- Are there assumptions that were made during the planning process that have turned out to be false (or not 100% true). During the schedule analysis process, it is extremely helpful if the assumptions were documented “in-line” within the schedule (in the notes field of the project schedule).
Note: This same thought process should be utilized for analyzing positive variances in the schedule. Analysis of positive variances helps you understand if you may have opportunities to improve the delivery date of key milestones, or at a minimum offset other negative variances.
Implementing Corrective Actions
Now that you have identified a potential problem in the schedule, and determined a reasonable explanation for the source of the variance, you need to decide on the appropriate next steps. The real decision you need to make is whether or not the variance should be formalized as a project impact (managed through the change control process). Considerations to help make this decision include:
- Is this variance permanent (the time lost will not be recovered), or temporary (it is a timing issue that will be recovered at some point in the future)? Generally, timing issues are not formalized as project impacts.
- Is the variance material? This is generally determined based upon whether or not it has an impact on a milestone that would be significant to the project sponsor or another stakeholder.
- Are there other actions or adjustments to the schedule that could be implemented to recover the time associated with the variance on this task? If with other actions this variance could be recovered, it would be treated in the same manner as timing variance.
- Will the variance have a direct impact on the milestone date, or is the milestone date “buffered” with a schedule reserve. If the milestone has a schedule reserve, you may decide to use all or part of the reserve to offset the variance (rather than formalizing it as a project impact). If you feel there is still significant risk associated with the milestone, it would probably be wise to formalize this project impact, and leave the schedule reserve “as is”.
If the decision has been made to formalize the variance as a project impact, you would initiate the change control as described in my blogs on Managing Change. After the project impact has been approved, you would likely re-baseline these tasks, establishing new dates, and eliminating the variance.
If the decision has been made not to formalize the variance as a project impact, you would document the explanation for the variance and the planned next steps associated with the variance. The best practice is to use the Notes field within the project schedule to document this type of analysis. During on-going schedule analysis you would continue to monitor the variance and explanation to ensure that the original decision not to formalize it as a project impact is still appropriate.
Schedule Performance Reporting
Schedule performance is a metric that is reported on a regular basis to the project sponsor and key stakeholders. In many cases it is incorporated into project status reports. In most cases it is a discussion topic during Project Steering Committee updates. For each of the summary tasks (project phases) or key milestones reported, the following information is provided on a regular basis:
- Planned (Baseline) vs. Projected (Current) Finish Date – Both of these data points are obtained directly from the schedule for the summary task or milestone.
- Variance – It is helpful to report the variance in terms of both days, and as a percentage of the total duration for the summary task or milestone. The variance is also obtained directly from the project schedule, and the variance percent is calculated based by dividing the variance by the total duration.
- Trend – Comparison of the variance to previous reporting periods. Is the metric trending positively, negatively, or holding steady?
- Comments – Explanation of the variance, and the next steps that are planned to monitor / manage the variance (including project impacts that have been initiated)
The information reported may be a summarization of several variance explanations documented during the schedule analysis process. Make sure the level of information is appropriate to the audience you are reporting it to. If a variance is formalized as a project impact, it would by default be reported to the project sponsors through the normal change control process.
Schedule Performance – Critical Success Factors
The accuracy and credibility of the schedule metrics and project performance management process are highly dependent on the following critical success factors:
- The first success factor is fairly obvious, but nonetheless the most important. The original baseline created, approved and saved in the project management tool, must be solid. If the baseline is not strong, comparisons to actual results will be difficult to explain and manage throughout the entire project life cycle.
- As project impacts are approved and implemented, the project schedule (or the portions impacted) must be re-baselined. If you do not re-baseline the schedule, the original variance will still be included in with any new variances that occur (confusing the on-going schedule analysis and reporting process).
- Another obvious success factor, and equally important, is that the schedule performance analysis is only as good as the schedule you are analyzing – the current schedule must reflect the current “reality” of the project. Therefore the schedule must be maintained and managed in a manner that keeps it in synch with the way that work is being performed by the team. This success factor includes:
- Timely and accurate progress updates (updating based upon the 25, 50, 75, 100 rule will be give you a good picture of progress on the project).
- Material changes to durations and work estimates should be adjusted within the schedule. These adjustments should be what moves task start and finish dates. Try to avoid manually adjusting dates (this will result in building unnecessary constraints into the project schedule).
- Make other adjustments required to keep the schedule in synch with the work to be performed (e.g., new tasks, changes in task sequence, and resource assignments).