This recommended practice (RP) is intended to serve as a guideline, not a standard. As a recommended practice of AACE International, the intent of the guideline is to improve the understanding and the communication among stakeholders involved with preparing, evaluating, and using project schedules. Various enterprises often misinterpret the quality and value of the information available to prepare schedules and the various methods employed during the scheduling process. It is understood that each enterprise may have its own project scheduling processes and terminology, and may classify schedules in their own particular ways. This guideline provides a generic and generally acceptable classification system that can be used as a basis of comparison. If an enterprise or organization has not formally documented its own schedule classification system, then this RP guideline can be used to provide an acceptable basis.

This recommended practice introduces a schedule classification system, which provides the guidelines for applying the general principles of schedule classification to project schedules. A schedule classification system maps the phases and stages of scheduling with a generic maturity and quality matrix that can be applied across a wide variety of industries. It is intended to be applied to any schedule in any industry, and across all stakeholders including government and academia.

A separate recommended practice provides a guideline for describing the specific use of schedule levels to project schedules. Schedule levels provide the details necessary to recognize the characteristics of each of the schedule levels for the purposes of communicating, executing (controlling and monitoring) and reporting the specific details of the project. Schedule levels consider reporting requirements for each of the stakeholders and the appropriate amount of information necessary for effective communication and decisions.

This recommended practice has been developed such that it:
• Provides common understanding of the concepts involved with classifying project schedules regardless of the type of enterprise or industry
• Fully defines and correlates the major characteristics used in classifying schedules so that enterprises may determine how their practices compare to these guidelines
• Uses degree of project definition as the primary characteristic to categorize schedule classes
• Reflects generally accepted practices in the cost engineering profession
This classification guideline is intended to help those involved with project schedules to avoid misinterpretation of the various classes of schedules and to avoid their misapplication and misrepresentation. Improving communications about schedule classifications reduces business costs and project cycle times by avoiding inappropriate business and financial decisions, actions, delays, or disputes caused by misunderstandings of schedules and what they are expected to represent.