Building the Preliminary Schedule

Now that we have our key inputs (WBS, task relationships, effort estimates, and resource assignments), we are ready to build our initial schedule. There are a few keys to remember here:

  • Use scheduling software and be properly trained in how to use it.images NoteA schedule is considered “preliminary” until resource assignments are confirmed.

Value of Scheduling Software

If you are not an advocate of scheduling software, or you need to help convince someone else in your organization, please note the following benefits provided by scheduling software:

  • Critical path analysis
  • Project and resource calendars
  • Schedule calculation
  • Resource leveling
  • Facilitate what-if analysis
  • Provide for top-down planning
  • Baseline management
  • If you’ve completed the other steps well up to this point, this step is much easier. For each task you want to schedule, you need to enter the following information:
    • Task name
    • Estimated effort
    • Predecessor task
    • Assigned resource
  • Understand the relationship between work, duration, resources, and productivity.images CautionOverallocated resources and misaligned schedule calendars are two of the most common causes of unrealistic project schedules.The duration of a task is dependent upon the number of resources (and their productivity rate) that are assigned to the total work effort.
  • Using the scheduling software, locate the critical path. Often, the software differentiates the tasks that comprise the critical path in some way, such as showing these tasks in red font.The critical path is the longest path through your network and represents the minimum amount of time it will take to complete the project.
  • Although the overall schedule development process should be a team-based activity, a single person generally performs the construction of the actual schedule, due to the nature of the software.images NoteFrequently, in the real world, project managers need to schedule to hard milestone dates or need to develop a schedule with less-than-complete work details. “When Reality Happens,” for helpful recommendations.

Perform Reality Check

In this step, we need to make sure the schedule is reasonable and is aligned with the organizational culture. The primary checkpoints are to check for proper allocation of resources and check for proper use of calendars.

When checking for proper allocation resources, you want to do two things: remove unrealistic work allocations and optimize the use of your resources.

This activity is commonly referred to as resource leveling. Most scheduling software systems provide a function to do this for you, but proceed with caution—the software does not always get this right. As a result, you can have a less-than-optimal schedule.

I recommend, especially if you are just beginning, that you manually level the allocation of your resources. As a result, you will learn more about your scheduling software and become more intimate with your schedule.

images Note

The only way to shorten a schedule is to compress the critical path time.

Review the resource schedule and look for any allocation that is more than the maximum hours per day or per week. In other words, if Joe Analyst is allocated for 16 hours on Monday, you have an unrealistic expectation. An adjustment needs to be made. The three common responses to resource overallocation situations are the following:

  • Utilize other resources. Assign one or more of the affected tasks to an available resource.
  • Establish a predecessor relationship. If Joe is the one who must perform each task, make the start of one task dependent on the finish of the other(s).
  • Modify the priority level of one or more of the tasks and let the software perform its resource leveling function.

To check for proper use of calendars, verify the following:

  • Are nonworking days accounted for (holidays or weekends)?
  • Are the number of work hours per day consistent with the organization’s expectation? Are eight hours of productivity per day assumed or something different?
  • For part-time resources or resources with special work schedules, are individual calendars assigned to them that reflect this reality?

Shorten the Schedule

On most projects, your preliminary schedule will not be the schedule presented to the stakeholders for approval. Due to either stakeholder expectations or an external deadline that must be met, an effort must be made to compress or shorten the schedule without reducing the scope of the project. The key to this effort is the critical path.

images Tip

You can also deploy techniques to shorten the project schedule during project execution as a corrective action to a schedule variance.

Clearly document and communicate all assumptions used in building the schedule.

The critical path determines the earliest (the soonest) your project can be completed given the current task relationships and estimated durations. As a project manager, you want to be very clear about which tasks comprise the critical path for two reasons:

  • If you can reduce this critical path (or change it), you might be able to complete the project sooner.
  • Any slippage in the completion of a critical path task pushes out the completion date for the entire project.

The common techniques to consider are detailed in Table 8.1.

TABLE 8.1 Techniques for Compressing the Project Schedule

TechniqueDefinitionKey Issue(s)
CrashingAdding resources to critical path activities only.Certain activities cannot be completed faster by adding resources. Additional resources often add overhead that can negate any time savings. Crashing can increase project costs.
Fast trackingPerforming critical path activities in parallel.Fast tracking is a high-risk technique that increases the probability of rework.
Process improvementsGaining productivity increases based on different work processes, technologies, or machinery.New approaches can increase project risks. Process improvements are not always available.
Limited overtimeIncreasing the number of hours per day or week available to work on project tasks.Overtime is most effective when used for limited periods of time. Overuse can lead to issues with team morale and quality of work.

Walk Through the Schedule

In our pursuit of both a more realistic schedule and a schedule that our stakeholders feel ownership for, you need to walk through the schedule with at least two groups—and if at all possible get a third quality-based review.

  • Review with project team—First, present the proposed schedule to your project team. Seek their feedback on all aspects: complete task listing, correct resource assignments, logical task sequence, reality factors, and so on. Make any necessary adjustments.
  • Quality review—This review is not always possible, but whenever possible, have an experienced and knowledgeable project scheduler review your proposed schedule before you submit it to your stakeholders. Especially if you are just gaining experience at this, this input and training can be invaluable.
  • Review with project stakeholders—Present the proposed schedule to key stakeholders. Seek feedback and questions on all aspects: verify resource assignments, risk responses, key milestones, and so forth. There are two keys to this step: one, the form and manner in which the schedule information is presented (making it as reviewer-friendly as possible), and two, investing the time to have a real-time, interactive review session.

Presenting the Schedule

One element of project planning and project management that is often overlooked is effectively communicating the project schedule to the various project stakeholders. Although presenting a detailed, tabular view of the schedule to the core team is acceptable, the use of visual summary representations of the schedule is highly recommended when presenting the schedule to other stakeholders. The common methods of presenting a project schedule summary are detailed in Table 8.2.

TABLE 8.2 Methods for Presenting a Project Schedule Summary

MethodKey AttributesBenefitsNotes
Milestone chartThis is a bar chart that shows start and end dates, major deliverables, and key external dependencies.Highlights key decision and completion points as well as any external dependencies.Milestone tables are also used (same information, no bar chart).
Gantt chartThis is a bar chart that shows the various levels of the WBS.Easy to read, incorporates the WBS, and can easily show actual progress against estimates.Usually does not show interdependencies.
Timeline summaryCombines aspects of a milestone chart and a Gantt chart.Summarizes critical path, key milestones, and relative duration of key activities. Excellent for executive presentations.Microsoft Project (starting with 2010) offers a feature called Timeline View that makes this method much easier to generate.
Network diagramA network diagram uses nodes and arrows. Date information is added to each activity node.Highlights the critical path and shows project logic (flow).For presentations, the summary task level of the WBS is generally used; otherwise, a network diagram is best suited for wall display.
Modified WBSUses the project WBS organization with status information added to each node.Shows progress against original work breakdown organization. Easy to read.Similar to network diagram type representations.

The Absolute Minimum

At this point, you should have a solid understanding of the following:

  • Schedule development is an iterative, team-based activity.
  • The project schedule is a critical component of the project plan and integrates all the key planning activities.
  • The project schedule drives the project budget and the resource schedule.
  • The project schedule is the project manager’s most effective tool in managing expectations regarding the key success factors (time, cost, and quality).
  • The five key inputs for the schedule are the WBS, effort estimates, task relationships, assigned resources, and planned risk responses.
  • Many reasons for an unrealistic schedule originate with an inadequate schedule development process and inadequate training with the scheduling software.
  • Document and clearly communicate all scheduling assumptions.

The map in Figure 8.6 summarizes the main points reviewed in this chapter.

An overview of developing a schedule.
FIGURE 8.6Overview of developing a schedule.

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