Triple Constraint

Project Management Topics

The Triple Constraint comprises of the Cost, Scope, and Schedule. The cost provides the financial details of the project also known as the project budget. The Scope is the tasks required to fulfill the project goals. The schedule contains the time necessary to complete the project. All three constraints work together in a project. A change to one will affect the other two.


Cost of work is of paramount concern when undertaking any project. Costs are derived from resources and material. External factors such as regulations and state of the economy will also impact the cost of work.

Various methods can be used to estimate the project costs.

  • Historical Data: Costs from similar past projects.
  • Resource Costs: Using pre-determined labor rates or the cost of goods.
  • Bottom Up: Estimating costs from the lowest level of the work package to the highest level of work package
  • Parametric: Statistical measurements between historical data and other project variables.  
  • Vendor Bid: Some projects bid out portions of the work, prior bid submissions can provide past pricing information
  • Reserve: Aggregate cost of activities


Scope deals with the specific project requirements and tasks necessary to complete the project.  A poorly managed project can lead to scope creep, over budget as well a late delivery. The scope can be properly managed by prioritizing tasks and assigning resources effectively.  

The stakeholder’s needs and requirements determine the scope. A project manager must juggle meeting their requirements if feasible while keeping the project on budget and on time.  Often, a stakeholder may have new requirements and will come up unexpectedly. A project manager should manage the stakeholder expectations without adding requirements that do not belong to the project scope. Requirements that do get added to the project must go through a formal change request.  In the event of long-term projects, there is a strong chance that new stakeholders may join the organization and introduce new requirements.


The schedule is the estimated amount of time the project will take to complete the deliverables. The schedule is determined by reviewing all the project tasks and how long it will take from start to finish.

Project Managers will utilize a Work Breakdown Structure (WBS) to break down the larger activities into smaller more manageable activities.

According to the Project Management Body of Knowledge (PMBOK®) there are seven steps for planning schedule:

  • Plan Schedule Management: create procedures and policies for planning, executing and controlling the project schedule.  
  • Define Activities: Defining what actions are required to produce the project deliverables. Sequence Activities:  The order in which the activities must be performed to complete the project while maintaining quality and efficiency
  • Estimate Activity Resources: How many resources are required to perform and complete each activity.
  • Estimate Activity Durations: The time it will take to complete the activity. The resource assigned to the activity will also determine the duration.
  • Develop Schedule: Review the activity, resources and the duration. This review and analysis Analyze activity, duration, resources, and timeline to develop a schedule
  • Control Schedule: Comparing planned schedule to actual progress

Although the Project Manager is ultimately responsible for the Project’s success, they rely on the team members to help keep on the Project on track.  

If you are looking to perfect your skills as a Project Manager join one of our Project Management classes. Already an experienced Project Manager and want to stand out, enroll in our PMP® Certification Bootcamp. 

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