CHAPTER 5

DEVELOP SCHEDULE

5.1 Introduction

Develop Schedule is the process of translating all of the WBS elements into a sequential, time-phased model for project execution. Resource loading the schedule model at the activity level is not required for the application of EVM; however, it is a recommended practice that lends credibility to the performance measurement baseline. Inputs and outputs are provided in Figure 5-1.

The project schedule integrates the activities associated with each WBS element and identifies dependencies between project activities as well as the dependencies that are external to the project. The schedule model can be decomposed and presented at various levels of detail.

This practice standard focuses on those schedule components having specific relevance to the practice of EVM. Therefore it is assumed, for purposes of this chapter, that scheduling processes as outlined in the PMBOK ^® Guide will be followed. For an overview of what is considered good practice on most projects most of the time for scheduling, refer to Chapter 6 on Project Time Management of the PMBOK^® Guide. For a more extensive treatment on the definition and implementation for project scheduling practices, refer to the Practice Standard for Scheduling [5].

5.2 Inputs

5.2.1 Scope Baseline

The scope baseline, comprised of the scope statement, WBS, and WBS dictionary, provides information on all of the product and project deliverables for the project against which delivery will be compared. The scope baseline should include sufficient information to allow project team members to decompose the work into the activities needed to complete the scope of work.

5.2.2 Resource Breakdown Structure

All resources required to complete the activities are identified including people, equipment, materials, supplies, and any other direct or indirect item required to execute the project. In some projects, sites and locations are also resources that may need to be considered for scheduling and cost estimating purposes.

5.3 Description

5.3.1 Schedule Tool

A schedule tool, in combination with a specific scheduling method (such as Critical Path Method), is used to enter the project-specific data including activities, logic sequence, duration estimates, resource estimates (if included), and other useful schedule-related information. The schedule tool processes and dynamically reacts to the project specific data entered into the tool to create a schedule model. The schedule tool selected for any project should include an integrated master schedule that lays out the total scope of the project from start to finish including key milestones and key stakeholder decision points.

5.3.2 Schedule Structure

The schedule model should be structured to reflect the logic of the WBS. The hierarchy may include:

• Higher levels of the WBS
• Control accounts
• Work packages and planning packages
• Activities

All activity relationships should be driven by the logic of the natural relationship between the activities.

5.3.3 Schedule and Budget Relationship

The relationship between the schedule model and the budgeting system is maintained throughout the life of the project. The planned value is derived using the same assumptions as the scheduling model. The same WBS and set of other budget elements (control accounts, work packages, and planning packages) will likely exist in both systems. Certain attributes of these, such as start and finish dates, budgets or “weighting,” and organizational responsibility, should always remain consistent between the budget and the schedule.

Once the project schedule model has been reviewed and agreed to by all the project stakeholders, it is saved and stored as the project schedule baseline, which forms the basis for the time-phased peformance measurement baseline. Chapter 10 of this practice standard addresses maintenance of the budget baseline. The same controls and discipline implemented to manage the budget baseline should be in place for the schedule baseline. For example, just as adjusting the budget baseline because of a cost overrun or underrun condition is discouraged, adjusting the schedule baseline due to an ahead or behind-schedule condition is also not a good practice and is discouraged.

5.4 Outputs

5.4.1 Integrated Master Schedule

The integrated master schedule represents the time phasing for execution of the project's scope of work. The project schedule should reflect the total project scope of work as defined in the WBS. It should be scheduled to a level of granularity and detail needed to plan, implement, and control the project. Both the high-level “master” schedule and the highest level of the WBS represent the overall project scope. Lower levels of the WBS correspond to equivalent levels of the schedule, with this concept extending to control accounts, work packages, and planning packages. Refer to Figure 5-2.

5.5 Considerations

5.5.1 Schedule Evolution

Project budgeting and scheduling are iterative processes involving the negotiation of project constraints until consensus estimates are achieved among the stakeholders. Therefore the schedule will continue to evolve until such time as the project manager establishes the performance measurement baseline.

5.6 Summary

A properly structured “integrated master schedule” depicts the project team's plan for work accomplishment. It provides the underlying logic for the performance measurement baseline, against which accomplishments will be measured and expected future outcomes will be forecast.

Scheduling from an EVM perspective includes:

• A logic-driven schedule that reflects the scope of work
• Schedule activities aligned to the WBS elements

The project schedule reflects the total project scope of work, as defined in the WBS, and should be scheduled to a level of granularity and detail needed to plan, implement, and control the project.