As a scheduler within various industries, I have been asked “What is Schedule Quality?” In fact, if you pose this question to various project personnel, you may receive more than one answer per individual! Why? Some view “schedule quality” as a simple series of measures and techniques. I believe that the pursuit of schedule quality is a multi-front battle.
The United States Government Accountability Office (GAO) Schedule Assessment Guide [1] contains a series of scheduling best practices with comprehensive descriptions of quality measures. Notably, the document discusses two critical components of schedule quality evaluation… quantitative measures and qualitative measures. Appendix I of the document is qualitative-oriented while Appendix III provides quantitative guidance.
From technical perspective, a critical-path-method schedule has compulsory elements. Tasks must have clear descriptions, logical links, and calculated values such as dates and float. Techniques which can undermine the schedule calculation should me minimized, such as hard constraints, unnecessarily complicated logic, overuse of leads and lags, and insufficient detail (high duration) activities.
Each of the items above can be measured. From an efficiency of time and cost standpoint, they are best measured in software designed for the purpose. In short, quantitative metrics are easy and quick to measure with the correct tool.
Can quality end here?
No. Quantitative metrics are the necessary starting point and foundation of the quality evaluation process. In fact, this metric-based evaluation should be performed early and often in the development of a proper project schedule. The lesson is that “building quality into the process” starts with the development of the schedule, rather than delaying such an evaluation until the schedule has been fully constructed.
The qualitative view requires the ability of the project team to answer the following question… “Does this schedule represent a meaningful, realistic view of project execution?” Quantitative metrics help with “meaningful,” but measuring “realistic” is a bit trickier.
Achieving schedule realism first requires an assessment by program personnel to determine if each step required in the development of the project goals is accurately and comprehensively captured in the schedule. The next step toward realism is an honest, thorough discovery of specific risks, opportunities, and the probability and potential impact of each. These may include events which can be controlled and mitigated and those which cannot (e.g. weather events).
A high quality schedule will pass quantitative validation (links, lags, float, etc…) while it also contains the results of qualitative diligence, such as scope verification and risk and opportunity integration. Without these elements, the schedule is not a roadmap to success… in fact, it may lead the team toward failure.