Scope control involves managing any changes to the agreed-upon scope of the project as defined by the Work Breakdown Structure (WBS). Scope changes are "fed back" through the planning processes, documents are updated, and performance measurements are adjusted accordingly. Scope control involves the acknowledgement of a scope change and advising stakeholders of the impact on the timeline and costs for the project. If a customer wants a barn built, but later adds windows and doors to the project after everyone has agreed to the previous requirements, the new windows and doors will likely impact the cost and timeline.
PMI separates the control areas of scope, schedule, cost, quality, and Risk control because their techniques tend to differ. Scope change, however, most closely follows the work to be accomplished as defined by the WBS. Therefore, any change to the work is a change to the scope.
The Difference Between Scope Verification and Quality Control
Scope verification differs from quality control in that scope verification ensures that the work product is formally accepted, whereas quality assurance ensures the correctness of the work product. These two concepts are very close to one another and are easily confused.
Scope verification is when the customer verifies that the product fulfills the requirements of the project. Quality assurance verifies that the product does what it's supposed to do and that it's fit for use.
An example of a product might be a baby stroller. A couple looks at several strollers and decides that one does, in fact, have the advertised features they are looking for. This qualifies as scope verification. The quality control angle for the same product would be the company performing measurements and tests to ensure the performance is correct. Although the couple buying the stroller might perform tests to see whether it is what they want, they will not be determining whether the wheels will fall off, except in a very cursory way.
Scope verification measurements may be taken at the end of project phases. Stakeholders may review the work results and deliverables to accept continuation of the project into the next phase. This is sometimes known as gate keeping.
Schedule control focuses on monitoring and evaluating the schedule baseline. Any monitoring and evaluation that occurs with schedule control heavily involves detecting schedule variances, both positive and negative, on the project schedule. Determining the cause of the variance is important in the early correction of a schedule variance. Performance reporting on a project schedule involves reporting on which planned dates have been met and which have not.
Planned start and end dates are key to understanding the rudiments of schedule variance. However, just because a task does not start on time does not mean your project is at risk. Understanding slack, critical path, and subcritical tasks is important in order to see whether variances in specific tasks make a difference to the overall schedule.
Variance analysis, through the use of earned value methods, described later, is the key technique for project time management. Yet, when schedule updates occur, a change to the timing of the project needs to take place. Not all schedule updates require adjustments to other parts of the project plan. Also, be aware that a schedule revision will require approval because it could change the start or finish date of the project.
Cost control focuses on monitoring actual project costs against the planned costs for the project. It involves understanding the variances, ensuring changes are approved and accurately reflected in the cost baseline, and informing stakeholders of the results. Earned value, discussed in the next section, is also a key tool for cost control.