Many of the techniques you will use to control the schedule for the PMP Certification Exam are similar to those you used to develop the schedule. You can see the techniques used in the Control Schedule process compared with the techniques used in the Develop Schedule process. The italicized techniques are similar or identical.
| Control Schedule | Develop Schedule |
|---|---|
| Performance reviews | Schedule network analysis |
| Project management software | Critical path method Critical chain method |
| Resource optimization techniques | Resource optimization techniques |
| Modeling techniques | Modeling techniques |
| Leads and lags | Leads and lags |
| Schedule compression | Schedule compression |
| Scheduling tool | Scheduling tool |
Performance reviews
Performance reviews compare the baseline with the actual results. You can compare several elements to determine the progress. The following is a list of common elements you can compare:
Planned start dates to actual start dates
Planned finish dates to actual finish dates
Planned duration to actual duration
Planned effort to actual effort
In addition, your review should include determining the amount of buffer or float you have used compared against how far along you are in the project. For example, if you have 30 days of float for the project, you’re halfway through, and you’ve used 21 days of float, that might be cause for concern.
You are 50 percent done but have used 70 percent of the float. Float is used for critical path methodology, and buffer is used for critical chain methodology.
Performance reviews shouldn’t just identify variances: They should also address the root cause of the variance and whether corrective or preventive actions are desired or even possible. Here are some of the common causes of schedule variances:
Staffing variances: If you were planning to have specific resources available but they’re not available, you might have a variance.
Change in priorities: When you planned the project, it was considered a high-priority project. However, things changed. When your project is no longer high priority, your resources might be available for less time than you planned.
Inaccurate estimating: If your duration estimates were too aggressive, you should expect a negative schedule variance.
Rate of work: Some people work really fast, and others work really slowly. The rate of work can affect how quickly you get work done.
Scope creep: Of course, if you add scope without analyzing the impact of budget and schedule, you will most likely be behind schedule.
A performance review can be as simple as reviewing your schedule and having the project management software identify variances, or it can be a very structured affair that includes the sponsor, the customer, and key vendors. These reviews can take several hours.
During the performance reviews, you should look at the current status as well as performance trends. Charts and graphs that forecast future schedule performance are a common method for assessing the schedule status. If the variance is negative and greater than your schedule threshold, you should consider various options for correcting the variances. It is common to present earned value (EV) data at performance reviews as well.
Resource optimization
Throughout the project, you may revisit your resource allocation among activities to try and optimize your resources. For example, you might move some resources to activities on the critical path if you’re concerned that those activities won’t finish on time.
Or you might find that work is taking longer than expected, and some resources are working 60-hour weeks. In that case, you might reduce the amount of work that they’re doing. Of course, this could have negative impacts, so you have to analyze your options and select the best one.
Modeling techniques
As the project progresses, your uncertainty in some areas will diminish, but it might increase in other areas based on the work performance. You can use what-if scenario analysis much the same way you do in planning by thinking through different scenarios that could affect the project and seeing what happens to the schedule based on those scenarios.
You can use this technique along with resource leveling to see the effect of shifting resources, adding resources, or reducing the amount of time that you’re using specific resources. You can also use what-if scenario analysis when analyzing the impact of risk events to see the impact on a schedule if a specific risk occurs.
A specific type of modeling technique is a simulation that calculates the duration based on differing assumptions. A Monte Carlo simulation will use three different estimates (optimistic, most likely, and pessimistic) to account for uncertainty in the duration and resource estimates. The output of a simulation is a probability distribution for the project duration.
Leads and lags
If you’re behind schedule, you may want to use leads to start successor activities before their predecessor activities are completed. For example, if the requirements gathering activities are taking longer than planned, you might start some of the preliminary design work before the final requirements documentation is complete.
Project management software and scheduling tool
Even though the PMBOK Guide lists project management software and the scheduling tool as two separate tools, they are essentially the same. Project management software can include more than just the scheduling tool: It can include budgeting and estimating software, resource management software, and so on. The point is that you have electronic tools to help you control your schedule.
The monitoring and controlling knowledge and skills that you should expect to see tested for the Control Schedule process include
Project performance metrics: specifically, effort, duration, and milestones
Variance and trend analysis techniques
Performance measurement techniques, specifically, CPM, PERT, SPI, and SV