The Impact of the Project Schedule

The project schedule is the tool that merges all of the work tasks to be performed, their relationships, their estimated durations, and their assigned resources to a calendar. Examples of partial schedules are illustrated in Figures 8.1 and 8.2. For most, specialized scheduling software (such as Microsoft Project) is used to produce a project schedule.

Figure 8.1. An example of a partial schedule displayed in table form.

Figure 8.2. An example of a partial schedule displayed in Gantt chart form.

As mentioned earlier in the book, the project schedule is often referred to as the "project plan" in error. While not technically correct, it is easy to understand why this term is often used. The project schedule serves as the chief integration point for most, if not all, of your project planning efforts. The project schedule reflects (or should reflect when the schedule development process is complete) all of the following:

• WBS
• Resource plan
• Work estimates
• Key milestones
• Responsibility assignments (RASIC)
• Quality management plan
• Risk management plan
• Communications management plan
• Procurement management plan
• Staff management (training) plan

In addition to providing this vital integration role, the project schedule is important to the project manager for these reasons as well:

• Drives project budget Since most of your project costs are a factor of time (we'll cover this in more detail in Chapter 9), the project schedule is a main driver for your project budget. If the schedule is inaccurate, your budget is likely incorrect too.
• Drives resource schedule Your schedule drives the timing of your resource needs. Especially in organizations where resources are shared across projects or centrally managed, the accuracy of the schedule is key to efficient resource management.
• Essential for managing expectations With a well-developed schedule, you have the best tool for managing stakeholder expectations regarding the schedule-cost-quality equilibrium. A well-developed schedule will illustrate the "earliest" date a project can be completed given the project's current requirements and constraints. This is an invaluable tool when negotiating the final schedule with senior management or customers and when assessing the impact of any change to equilibrium factors during the execution of the project.
• Allows project performance to be measured With a well-developed and approved project schedule, you now have the ability to establish a baseline for how the project is actually performing. We will discuss this in more detail in Chapter 10, "Controlling a Project."
• Provides for "what-if" analysis capabilities Another important ability that a well-developed schedule provides is the ability to perform "what-if" analysis during the execution of the project. Over the course of a project, things happen that can negatively impact project performance. At these times, you will often be asked what corrective actions can be taken to possibly get the project back on schedule. Without a well-developed schedule, you will not be able to quickly determine the impact of implementing a given schedule compression technique, such as fast-tracking, crashing, or limited overtime.