Practice Standard for Scheduling - Third Edition

• Publisher: Project Management Institute
• Year: 2019
• ISBN:
  9781628255621
• Edition: 1
• Topic: Business
• Subtopic: Project Management
• Index: Business

Practice Standard for Scheduling—Third Edition provides the latest thinking regarding good and accepted practices in the area of scheduling for a project. This updated practice standard expounds on the information contained in Section 6 on Project Schedule Management of the PMBOK® Guide. In this new edition, you will learn to identify the elements of a good schedule model, its purpose, use, and benefits. You will also discover what is required to produce and maintain a good schedule model. Also included: a definition of schedule model; uses and benefits of the schedule model; definitions of key terms and steps for scheduling; detailed descriptions of scheduling components; guidance on the principles and concepts of schedule model creation and use; descriptions of schedule model principles and concepts; uses and applications of adaptive project management approaches, such as agile, in scheduling; guidance and information on generally accepted good practices; and more.

1

INTRODUCTION

The Practice Standard for Scheduling provides the framework to create, manage, and maintain schedules in a project environment. This practice standard contains five main sections. Each section provides additional information on the content and terminology used in this practice standard:

Section 1—Introduction. This section provides an introduction to scheduling and its benefits, as well as an overview of the development and use of schedule models.

Section 2—Schedule Model Principles and Concepts. This section provides guidance and information on the principles and concepts associated with schedule model creation and use within predictive, adaptive, or hybrid environments.

Section 3—Schedule Model Good Practices Overview. This section provides guidance and information on generally accepted good practices associated with the planning, developing, maintaining, communicating, and reporting processes of an effective critical path method (CPM) schedule model approach.

Section 4—Scheduling Components. This section provides a detailed catalog of the potential components of a CPM scheduling tool.

Section 5—Conformance Index. This section provides an overview of the conformance index process. It provides a method for assessing how well a CPM schedule model incorporates the components, guidelines, definitions, behaviors, and good practices outlined in this practice standard.

Appendixes contained in this practice standard are:

Appendix X1—Third Edition Changes

Appendix X2—Contributors and Reviewers of the Practice Standard for Scheduling – Third Edition

Appendix X3—Conformance Assessment Scoring Table

Appendix X4—Conformance Assessment Worksheets

Appendix X5—Forensic Schedule Analysis

This practice standard includes adaptive approaches such as agile (see Sections 2.2.3 and 2.6). However, the majority of the content of this practice standard, except where indicated, describes a traditional (i.e., predictive) approach to scheduling using CPM. Additional information on agile may be found in the Agile Practice Guide [1].¹

Section 1 provides an overview of the content of this practice standard and is divided as follows:

1.1 Project Scheduling

1.2 Why Scheduling?

1.3 Overview

1.4 Purpose

1.5 Applicability

1.1 PROJECT SCHEDULING

Project scheduling ensures the development of effective schedule models through the application of skills, tools, techniques, and intuition acquired through knowledge, formal and informal training, and experience. A schedule model rationally organizes and integrates various project components (e.g., activities, resources, and logical relationships) to optimize the information available to the project management team and facilitate the likelihood of a successful project completion within the approved schedule baseline. Key schedule model terms are defined as follows:

• Milestone. The PMI Lexicon of Project Management Terms [2] defines a milestone as: A significant point or event in a portfolio, program, or project. For the purposes of this standard, a milestone is a significant point or event in a project defined with a duration of zero time periods.
• Activity. The Lexicon [2] defines an activity as: A distinct, scheduled portion of work performed during the course of a project. For the purposes of this standard, an activity is a unique and distinct scheduled portion of work with a duration greater than zero time periods, to be performed during the course of a project.
• Resource. A skilled human resource (specific disciplines either individually or in crews or teams), equipment, services, supplies, commodities, materials, budgets, or funds required to accomplish the defined work.
• Logical relationship. A dependency between two activities or between an activity and a milestone.

The terms scheduling tool, schedule model, schedule model instance, and schedule presentation are defined in the glossary of this practice standard and described as follows:

• Scheduling tool. A tool that provides schedule component names, definitions, structural relationships, formats, and algorithms for schedule calculation that support the application of a scheduling method.
• Schedule model. A representation of the plan for executing the project's activities including durations, dependencies, and other planning information, which is used to produce a project schedule along with other scheduling artifacts. The schedule model is dynamic and is developed and maintained by the project team with input from key stakeholders. It applies a selected scheduling approach to a scheduling tool using project-specific data. The schedule model can be processed by a scheduling tool to produce various schedule model instances.
• Schedule model instance. A version of the schedule model that has been processed by a scheduling tool based on inputs and adjustments made to the project-specific data within the scheduling tool. The scheduler saves the schedule model instances as project records and for reference, including data date, version (based on a completed update cycle), target schedule models, and the baseline schedule model. The instances can produce various schedule presentations. When used together, the instances support report generation and analysis, such as variance and risk analysis.
• Schedule presentation. An output published from a schedule model instance used to communicate project-specific data for reporting, analysis, and decision making. Presentations may include bar charts, critical paths, near critical paths, resource profiles, activity assignments, baselines, record of accomplishments, risks/issues, etc. Presentations can also provide time-based forecasts and identify performance deviations throughout the project's life cycle.

1.2 WHY SCHEDULING?

Projects are complex temporary endeavors; however, a detailed schedule model that contains logically related work allows the project to be simplified into manageable phases or groupings of activities. These phases or groupings allow management to optimize the trade-offs between scope, cost, and schedule. Project performance is reported and monitored when progress against these activities and milestones is recorded within the schedule model. As progress is recorded on a project, the remaining effort, as defined in the approved baseline, requires reassessment. The execution of a project often proceeds differently than the initial plan and baseline. In a typical project environment, it becomes necessary to refine the schedule model because of (a) incomplete or inadequate planning, (b) further decomposition of the project scope, (c) significant project changes, (d) organizational changes, or (e) environmental changes. This iterative evolution is required to predict, recognize, and address those evolving factors and issues that could potentially affect project performance.

The key to project success is applying knowledge and experience to create a credible project management plan. The project management plan optimally balances cost, resources, scope, and time-based performance with the project team's commitment to execute the project in accordance with the plan. Scheduling is one of the basic requirements of project planning and analysis. The schedule model, once completed, becomes an effective planning tool for (a) engaging communications that focus on optimizing future actions, (b) assisting proactive collaboration, and (c) creating a project performance management system.

Scheduling provides the detail that represents who, how, where, and when the assigned project resources will deliver the products, services, and results defined in the project scope. The detailed plan serves as a tool for managing the activities to be performed, communications, and stakeholder expectations. It also serves as a basis for performance reporting. The project manager together with the project team use the project schedule (baseline and actual progress) as a primary tool for planning, executing, and controlling all project-based evolutions. The schedule model is used to track, forecast, and monitor project performance throughout its life cycle.

The dynamic nature of a project's execution is best served by a tool that allows for modeling of the project, the project's internal and external dependencies, and analysis due to the impact of progress and risk events. The model concept looks for the schedule model to react to inputs (progress updates, progressive elaboration, changes to scope definition (WBS), etc.) as the project team expects the project to perform based on those inputs. The following are examples of how the schedule model supports the project by allowing for:

• Time phasing of required activities;
• Constraints that limit the options for managing a portfolio, program, project, or process;
• Resource planning;
• Mobilization of planned resources in a most efficient manner;
• Coordination of events within the project and among other projects;
• Visual representation of these schedule issues to the stakeholders;
• Early detection of risks, problems, issues, or opportunities;
• Implementation of actions to achieve the project objectives as planned;
• What-if and variance analysis;
• Cost planning; and
• Forecasting of estimate at complete and to complete.

1.3 OVERVIEW

This practice standard describes schedule model components (see Section 4) and generally recognized good practices for scheduling processes. Generally recognized means that the knowledge and practices described are applicable to most projects most of the time. Additionally, there is consensus about the value and usefulness of knowledge and practices. Good practice means that there is general agreement that the application of these skills, tools, and techniques can enhance the probability of success over a wide range of projects. Good practice does not mean the knowledge described should always be applied uniformly to all projects—it means the project team is responsible for determining what is appropriate for any given project. The proper use of the components and their practices results in a schedule model usable for planning, executing, monitoring, and closing, in addition to the delivery of the project scope to stakeholders. Although additional schedule approaches and life cycles are included, this practice standard describes a traditional (i.e., predictive) approach to scheduling using the CPM approach.

Schedule model creation begins with selecting a scheduling approach and a scheduling tool that support the desired scheduling approach. Next, starting with the WBS, project-specific data are incorporated within the scheduling tool to create a unique schedule model. Schedule model instances are snapshots captured from the schedule model. Schedulers produce various presentations from these schedule model instances based on the project-specific data. See Figure 1-1 to better understand the interrelationships of the schedule model creation concepts and terminology. This process results in a schedule model for project execution, monitoring, and control that responds predictably to progress and changes. The model is also used for engaging communications toward proactive optimization of future actions. The scheduler should regularly update the schedule model to reflect progress and changes such as scope, durations, milestones, allocated resources, productivity rates, means of accomplishment, variances, risk evaluations, and scheduling logic.

This practice standard also provides an assessment that can be used to determine how well the schedule model conforms to this practice standard. A conformance index (see Section 5 of this practice standard) is developed by determining which components are used and how they are used within the schedule model. In order to obtain an acceptable conformance assessment, a schedule model, at a minimum, should contain all of the required components described in Section 4 and Appendix X3. The selection of an appropriate scheduling software tool provides access to the required components necessary to develop the schedule model. The use of this practice standard, along with experience, skill, and organizational maturity, provides the appropriate guidance for applicat...