6.5.1 Inputs to Schedule Control

.1 Project schedule.The project schedule is described in Section 6.4.3.1. The approved project schedule, called the schedule baseline (which must be feasible technically and in terms of resources), is a component of the project plan described in Section 4.1.3.1. It provides the basis for measuring and reporting schedule performance.

.2 Performance reports. Performance reports, discussed in Section 10.3.3.1 provide information on schedule performance such as which planned dates have been met and which have not. Performance reports may also alert the project team to issues that may cause problems in the future.

.3 Change requests. Change requests may occur in many forms—oral or written, direct or indirect, externally or internally initiated, and legally mandated or optional. Changes may require extending the schedule or may allow accelerating it. (see Section 4.3.1.3).

.4 Scope management plan. The scope management plan is described in Section 6.4.3.3.

6.5.2 Tools and Techniques for Schedule Control

.1 Schedule change control system. A schedule change control system defines the procedures by which the project schedule may be changed. It includes the paperwork, tracking systems, and approval levels necessary for authorizing changes. Schedule change control should be integrated with the integrated change control system described in Section 4.3.

.2 Performance measurement. Performance measurement techniques, described in Section 10.3.2, help to assess the magnitude of any variations that do occur. An important part of schedule control is to decide if the schedule variation requires corrective action. For example, a major delay on a noncritical activity may have little effect on the overall project, while a much shorter delay on a critical or near-critical activity may require immediate action.

.3 Additional planning. Few projects run exactly according to plan. Prospective changes may require new or revised activity duration estimates, modified activity sequences, or analysis of alternative schedules.

.4 Project management software. Project management software is described in Section 6.4.2.5. The ability of project management software to track planned dates versus actual dates and to forecast the effects of schedule changes, real or potential, makes it a useful tool for schedule control.

.5 Variance analysis. Performance of the variance analysis during the schedule-monitoring process is a key element for time control. Comparing target dates with the actual/forecast start and finish dates provides useful information for the detection of deviations and for the implementation of corrective solutions in case of delays. The float variance is also an essential planning component to evaluate project time-performance. Particular attention has to be given to critical and subcritical activities (i.e., analyzing the ten subcritical paths, in order of ascending float).

6.5.3 Outputs from Scope Change Control

.1 Schedule updates. A schedule update is any modification to the schedule information that is used to manage the project. Appropriate stakeholders must be notified as needed. Schedule updates may or may not require adjustments to other aspects of the project plan.
  Revisions are a special category of schedule updates. Revisions are changes to the scheduled start and finish dates in the approved project schedule. These changes are generally incorporated in response to scope changes or changes to estimates. In some cases, schedule delays may be so severe that rebaselining is needed to provide realistic data to measure performance. However, care must be taken before rebaselining, as historical data will be lost for the project schedule. Rebaselining should only be used as a last resort in controlling the schedule; new target schedules should be the normal mode of schedule revision.

.2 Corrective action. Corrective action. Corrective action is anything done to bring expected future schedule performance in line with the project plan. Corrective action in the area of time management often involves expediting: special actions taken to ensure completion of an activity on time or with the least possible delay. Corrective action frequently requires root-cause analysis to identify the cause of the variation, and schedule recovery can be planned and executed for activities delineated later in the schedule and need not only address the activity causing the deviation.

.3 Lessons learned. The causes of variances, the reasoning behind the corrective action chosen, and other types of lessons learned from schedule control should be documented, so that they become part of the historical database for both this project and other projects of the performing organization.