Mastering the Art of Scheduling How to Avoid Costly Scheduling Errors

Mastering the Art of Scheduling: How to Avoid Costly Scheduling Errors

Scheduling in project management is a delicate balance of planning and execution. Schedules are central to a project’s success, and the most skilled practitioners anticipate changes and plan accordingly to ensure that they complete their projects on time and within budget. Poor planning and failure to account for unforeseen risks cause delays and tax resources, which is why project scheduling is one of the most critical elements of project management.

Only through organization, efficiency, and transparency can you master the art of scheduling and become a true expert project manager. Like ancient warriors who trained for years to perfect their techniques, project managers must also hone their skills to create and maintain accurate and reliable schedules.

In the digital age, business priorities can shift at a moment’s notice, and project managers must be able to adapt and update schedules constantly to reflect any alterations in the timeline or milestones of the project. Never view your project scheduling as set in stone; effective scheduling involves monitoring and updating the schedule as needed as/when project priorities shift. With the right skills and techniques, you, too, can master project scheduling.

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Scheduling in Project Management

A project schedule is how project managers plan, track, and communicate the timeline and milestones of a project, keeping all team members and stakeholders aligned. The schedule is typically a living document that details all the tasks the project team must complete to wrap up the project on time and within budget. This document also allows senior management to adjust the project schedule baseline as needed while ensuring alignment for all stakeholders and team members on each task’s approximate start and end dates.

While the frequency of schedule updates depends on a project’s needs, the best practitioners know that regular updates are essential to avoid costly errors. Whether the project is complex and requires daily updates or is small enough to only need weekly updates, creating and maintaining a detailed and accurate project schedule is central to successful project management. Poorly organized and unrealistic schedules can cause budget issues and threaten the overall success of a project.

At the beginning of the project planning process, schedules should be high-level, focusing on major tasks and milestones. As clients finalize their requirements, tasks will change or be removed from the project altogether. After the scope of work is finalized, you can dig into the scheduling details.

When it comes time to create a schedule, project managers use three types of project schedules:

Milestone Charts

Milestone charts are a great tool for visualizing the work in progress. Given the volume of work underway at any time, project managers need a tool that allows them to see the project’s progress. That’s where milestone charts come in. These schedules provide a high-level overview of the project timeline, so you can see the team’s progress and measure it against the project schedule.

Gantt Charts

A Gantt chart is a bar chart that shows the start and end dates of each task in a project. Its function is similar to a milestone chart in that it helps project managers visualize the schedule and track progress. A Gantt chart positions the timeline on the x-axis and the various project tasks stack on the y-axis. Gantt charts are a cross between the milestone chart and the master schedule in that they allow you to visually track project progress in greater detail.

Master Project Schedule:

A master project schedule contains information about every task in the project. They explain all primary deliverables within the project and the work components necessary to complete these tasks. This type of project schedule is usually much more detailed than a Gantt or milestone chart. Project managers usually turn to their master projects schedule to track progress and ensure the project deadlines are on track.

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What are Scheduling Errors?

Because a project schedule is essential to successful project management, it serves several core functions, including:

  • Helping project managers plan and track a project’s timeline
  • Communicating the project timeline to all stakeholders
  • Preventing the project from exceeding its budget
  • Ensuring that the project is completed on time

Scheduling errors are the result of planning oversights that cause a schedule to be disorganized, unrealistic, out of scope, and at risk of failing to meet the entire project timeline.

8 Most Common Project Scheduling Errors

Given the volume of moving parts a project manager is responsible for, it’s easy to make mistakes. However, if you know the common scheduling errors project managers make, you can avoid making them. The eight most common project scheduling mistakes are:

  1. Failing to perform risk management and neglecting to take into account time for unforeseen events
  2. Not following a clear structure
  3. Failure to realistically estimate resources needed to complete a project
  4. Failure to adopt an Agile Mindset when appropriate
  5. Not prioritizing tasks properly
  6. Failing to identify all critical stakeholders and their requirements.
  7. Overlooking interdependencies and external constraints
  8. Assigning a project deadline before agreeing on the scope of work

How to Avoid Costly Scheduling Errors

While you can’t control every unforeseen circumstance that impacts scheduling, there are steps you can take to mitigate them. Some steps you can take to prevent scheduling mistakes in your next project include:

Prioritize risk management

You can never completely foresee or control risks during a project’s lifecycle, but risk management can ensure schedule buffers exist for the probable risks that can impact the project schedule. Developing a culture of and processes for identifying and managing risk is necessary to keep projects on track. Identify risk trigger events and use the monitor risk process to prepare for both threats and opportunities, including designing and implementing response plans and reacting to new risks as they arise.

Know when to use a Traditional Waterfall or Agile approach

Project managers need to determine the appropriate management method for each project they work on, as there is no single approach that works in every situation. To select the correct approach, you must understand the nature of the project to determine whether Waterfall, Agile, or a hybrid form should be used. Knowing when to include Agile project management elements when appropriate can be particularly useful if your team needs to complete a set of tasks in a shorter scheduling window.

Ensure that the view of resource availability that the plan is built on is realistic

Resource availability is the number of resources required to finish a project and the amount of time each resource needs to dedicate to project work. If your project plan has unrealistic resource availability, it will be doomed to suffer delays and budget constraints before it even starts.

Conduct stakeholder identification and analysis continuously

You shouldn’t expect to run stakeholder analysis once at the beginning of a project and then neglect it for the rest of the project life cycle. Stakeholders can request disruptive scope changes that directly impact everything from costs to scheduling. You need to understand which stakeholders will affect your project and then effectively communicate with all of them for the duration of the project.

Ensure that the prioritization of tasks reflects customer requirements

Delivering prioritized customer requirements first can help insulate your project against unforeseen changes. If the scope of work changes, you want to ensure you have delivered the customer requirements that benefit them the most.

Utilize SMEs to identify critical dependencies

As much as you want to control every aspect of a project’s lifecycle, project management is a collaborative art form. SMEs can provide input on technical processes, strategies, and resources and help you develop accurate timelines and budgets. Because SMEs have a high level of experience and expertise in areas you may not, utilizing them to complete essential project tasks can help you keep on, if not ahead of, schedule.

Allow the Scope of Work to drive the project deadline when possible

All too often project managers make a critical scheduling mistake by starting with a self-imposed deadline and attempting to back-solve a plan to meet that deadline. The scope of work, quality requirements, and resource allocation should drive the finish date of the project, not the other way around, unless required by some external deadline, such as a government-mandated deadline.


It’s not an exaggeration to say that creating and maintaining project schedules is a fine art. A good schedule puts project teams in the best position to succeed and complete projects in a timely and budget-friendly manner. At its core, the project schedule is a list and timetable illustrating all the tasks that need to be completed during the project lifecycle. Errors in the scheduling process can have significant ramifications for the overall success of a project. Not only do project managers need to complete the preparatory steps to avoid scheduling mistakes, but they also must consistently update the project schedule. If you put in the time and effort to develop and maintain an accurate, detailed schedule, you will dramatically increase your team’s chance of success.

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Erin Aldridge, PMP, PMI-ACP, & CSPO
Director of Product Development at
Erin Aldridge, PMP, PMI-ACP, & CSPO