What is a Project Management Triangle?

A project management triangle is a helpful visual tool that represents the three constraints that define any given project: scope, cost, and schedule. No matter what a project might be—a piece of software, a building, a new marketing plan—it is limited by these three things. Furthermore, each of the three is connected to the other two, so that decreasing the budget of a project, for instance, will likely lengthen its schedule or force the creation of a new, more modest scope.

Below we will look at each point on the project management triangle in turn.


A project’s “scope” is its ultimate overall goal. The scope should be as detailed and specific as possible, and made clear to all the project’s stakeholders (the people involved in the project) during the earliest phases of the project. Defining the project’s scope as clearly as possible will realistically determine what budget is required and how much time it will take to complete it. Any subsequent change in scope will naturally also change the budget and the timeline.


All projects, of course, cost money. A project manager should have a definite, realistic estimate of the project’s cost before he or she begins to implement that project. The cost of material and human resources, as well as indirect costs, must be considered, and allowance must be made for risks that might result in increased costs. Creating an accurate cost estimate is therefore a complicated process, and there are a variety of methods of doing so. Many project management software programs include tools that assist managers in this endeavor.


The schedule of a project, like the budget, needs to be determined during the project’s planning stage, and it is one of the project manager’s paramount duties to ensure that the project is on schedule, or, if not, finding ways to address that problem. Creating a schedule is not as simple as merely looking at all the tasks that must be performed, guessing how much each should take, and adding them together. The manager must ask if there will be dependencies (that is, tasks that depend upon other tasks), and which tasks are of the highest priority and which are less critical.

According to the Project Management Institute, there are six processes involved in managing the schedule of a project:

  • Defining the project’s activities
  • Determining the appropriate sequence of activities
  • Estimating the resource needs of each activity
  • Estimating the length of each activity
  • Developing a schedule
  • Controlling the schedule


A successful project manager needs to always keep in mind the critical factors of scope, cost, and schedule. Balancing these constraints is the key to keeping the project under control and ensuring that the final outcome is a success.