Key Elements of Successful Schedule Management: Part 1

A successful schedule helps in both the management of project execution and in the evaluation of Change Orders that include time extensions and claims involving delay and acceleration. This is the first of two blog posts on key elements of scheduling that contribute to successful schedule management. This post covers contractual requirements, the work breakdown structure, project scope, schedule logic, and the critical path. The second post will address resource loading and leveling, schedule accuracy, and developing and maintaining the change control process.

Contractual Requirements
Scheduling and reporting requirements vary among projects. A prudent contractor develops a scheduling program that complies with contractual requirements so the owner can review and critique the contractor’s schedule submittals to ensure the schedules and updates adhere to contract provisions. The schedule should accurately document the contractor’s baseline plan and actual progress and serve as a document that protects the interests of the parties in the case of a delay or acceleration issue or dispute.

Work Breakdown Structure
Creating the schedule starts with breaking down planned tasks into definable and manageable categories. The Work Breakdown Structure (WBS) provides a common framework for organizing, planning, and controlling the total scope of work. It also serves as a basis for assigning resources to schedule activities. Breaking work into WBS classifications makes complex schedules more manageable. The level of detail of the WBS should allow activity coding to support the project and should keep the schedule controllable. When defining the level of detail of the WBS, consider these factors:

• The duration of the schedule activities in the lowest level of detail of the WBS should not be longer than the contractual reporting period. For example, if the established reporting period for the project is once a month, then the duration for any single activity should be less than one month long.
• It should be possible to estimate the cost and duration of each WBS element.
• Every WBS element should have a definable beginning and end date.
• Activities can be assigned to specific individuals and parties by responsibility.
• The level of detail for the activities should be reasonable, and it should be impractical to break down the work any further.
• The execution performance of the activities should be measurable.
• The work packages that the WBS defines should each be unique and not overlap one another.
• Each WBS level should be easily rolled up to the next higher level.

Project Scope
The schedule is only as good as the level of detail that is available when the baseline schedule and schedule updates are prepared. If the project’s design is conceptual, preliminary, or incomplete, then the schedule is similarly incomplete. It is important to periodically update the schedule as design detail progresses.

The schedule encompasses the full work scope for a project and should reflect activities and work sequences that are based on collective input from all parties, including project management, engineering, procurement, field supervision, the contractor, subcontractors, etc. It is important to solicit and include input from all parties to help prevent future schedule conflicts as well as encourage the parties’ collective ownership and acceptance of the schedule.

Schedule Logic
The logic for a schedule includes activity durations, interrelationships among activities, and relationship lag and lead durations. Typically, schedule logic is based on company, team, or individual experience on similar types of projects. It is essential to recognize that although two projects may be similar, there are variables that differentiate them and may affect performance. For example, various owners may have distinct requirements and demands, different locations may present diverse challenges and constraints, and availability of skilled labor may affect activity durations.

The project’s cost estimate can also serve as a foundation for developing activity durations. Depending on the level of detail, the estimate may provide man-hours and possibly crew compositions for each task. Estimating crew hours can be simple: divide the total man-hours for an activity by the number of workers in the crew. Then divide the crew hours by the number of work hours per day to calculate the estimated number of workdays. This duration can then be adjusted to account for crew inefficiencies, standby time, contingencies, and other factors. If the estimate includes man-hours but not crew composition, the crew size can be inferred based on prior experience.

Assessing the logic requirements among the activities in a schedule involves determining the sequence and establishing the types of relationships among activities. The objective in developing the logic is to accurately estimate the types of activity connections that are required to complete the work efficiently. The interrelationships among the tasks are primarily based on the planner’s previous experience in addition to considering any requirements or factors that are specific to the project and that drive the sequence and completion of the work. If the schedule logic is incorrect, activities will start out of sequence and may be delayed.

Critical Path
Once activities are identified and logic ties are addressed, the schedule’s critical path is ready for review. The critical path is the chain of activities in the schedule with the lowest total float that comprises the longest continuous sequence of activities through the schedule from project start to completion. A schedule may contain more than one critical path, or various near-critical paths that are within a few days of the critical path. As a project progresses, the critical path can change. In an accurate schedule, critical path activities should realistically represent the scope of work for the project that cannot be delayed without extending the project completion date. If the critical path includes minor, inconsequential activities whose inclusion on the critical path is questionable, then any constraints and logic controlling the critical path activities should be reevaluated to ensure the validity and reasonableness of the critical path.

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