Just before the end of 2015 the GAO (Government Accountability Office) released its Schedule Assessment Guide: Best Practices for Project Schedules. This has been a long time in the making. It was originally started in November 2010 with a draft released in 2012 for comment. The GAO Schedule Assessment Guide develops scheduling concepts and presents them as ten best practices associated with developing and maintaining a reliable, high-quality schedule. The GAO Schedule Assessment Guide also presents guiding principles for auditors to evaluate certain aspects of government programs.
Ten Best Practices
The ten best practices associated with a high-quality and reliable schedule and their concepts are as follows.
1. Capturing all activities.
The schedule should reflect all activities as defined in the program’s work breakdown structure (WBS), which defines in detail the work necessary to accomplish a project’s objectives, including activities both the owner and the contractors are to perform.
2. Sequencing all activities.
The schedule should be planned so that critical program dates can be met. To do this, activities must be logically sequenced and linked—that is, listed in the order in which they are to be carried out and joined with logic. In particular, a predecessor activity must start or finish before its successor. Date constraints and lags should be minimized and justified. This helps ensure that the interdependence of activities that collectively lead to the completion of activities or milestones can be established and used to guide work and measure progress.
3. Assigning resources to all activities.
The schedule should reflect the resources (labor, materials, travel, facilities, equipment, and the like) needed to do the work, whether they will be available when needed, and any constraints on funding or time.
4. Establishing the duration of all activities.
The schedule should realistically reflect how long each activity will take. When the duration of each activity is determined, the same rationale, historical data, and assumptions used for cost estimating should be used. Durations should be reasonably short and meaningful and should allow for discrete progress measurement. Schedules that contain planning and summary planning packages as activities will normally reflect longer durations until broken into work packages or specific activities.
5. Verifying that the schedule can be traced horizontally and vertically.
The schedule should be horizontally traceable, meaning that it should link products and outcomes associated with other sequenced activities. Such links are commonly referred to as “hand-offs” and serve to verify that activities are arranged in the right order for achieving aggregated products or outcomes. The schedule should also be vertically traceable— that is, data are consistent between different levels of a schedule. When schedules are vertically traceable, lower-level schedules are clearly consistent with upper-level schedule milestones, allowing for total schedule integrity and enabling different teams to work to the same schedule expectations.
6. Confirming that the critical path is valid.
The schedule should identify the pro- gram’s critical path—the path of longest duration through the sequence of activities. Establishing a valid critical path is necessary for examining the effects of any activity’s slipping along this path. The program’s critical path determines the program’s earliest completion date and focuses the team’s energy and management’s attention on the activities that will lead to the project’s success.
7. Ensuring reasonable total float.
The schedule should identify reasonable total float (or slack)—the amount of time a predecessor activity can slip before the delay affects the program’s estimated finish date—so that the schedule’s flexibility can be determined. The length of delay that can be accommodated without the finish date’s slipping depends on the number of date constraints within the schedule and the degree of uncertainty in the duration estimates, among other factors, but the activity’s total float provides a reasonable estimate of this value. As a general rule, activities along the critical path have the least total float. Unreasonably high total float on an activity or path indicates that schedule logic might be missing or invalid.
8. Conducting a schedule risk analysis.
A schedule risk analysis starts with a good critical path method schedule. Data about program schedule risks are incorporated into a statistical simulation to predict the level of confidence in meeting a program’s completion date; to determine the contingency, or reserve of time, needed for a level of confidence; and to identify high-priority risks. Programs should include the results of the schedule risk analysis in constructing an executable baseline schedule.
9. Updating the schedule using actual progress and logic.
Progress updates and logic provide a realistic forecast of start and completion dates for program activities. Maintaining the integrity of the schedule logic is necessary to reflect the true status of the program. To ensure that the schedule is properly updated, people responsible for the updating should be trained in critical path method scheduling.
10. Maintaining a baseline schedule.
A baseline schedule is the basis for managing the program scope, the time period for accomplishing it, and the required resources. e baseline schedule is designated the target schedule and is subjected to a configuration management control process. Program performance is measured, monitored, and reported against the baseline schedule. The schedule should be continually monitored so as to reveal when forecasted completion dates differ from baseline dates and whether schedule variances affect downstream work. A corresponding basis document explains the overall approach to the program, defines custom fields in the schedule file, details ground rules and assumptions used in developing the schedule, and justifies constraints, lags, long activity durations, and any other unique features of the schedule.
The Negatives of Risk and Uncertainty
There have been initial comments in some of the industry forums regarding the lack of emphasis on risk analysis and uncertainty analysis. One person commented that the guide relegates “systemic” risks to unknown-unknown purgatory while it does not emphasize historical experience in validation or risk analysis (statistical simulation not necessary for parametric analysis), and also fails to apply risk analysis as a way to fix the schedule, not just to get a range.
Overall, a great guide that any folks will find incredibly useful. This guide promotes scheduling best practices that organizations working for the US Government should adhere to. In fact, the guide should be the basis of scheduling practices for all companies managing projects. Although the guide is over 200 pages long, it’s filled with common sense guidelines that have been corroborated by both industry and academic institutions alike.