The triple constraint theory argues that every project operates within the boundaries of cost, time, and scope. Importantly, these constraints are inextricably linked. When a business asks for a project to be completed in less time, this causes the cost to rise. When a business wants to save money on cost, the scope must be simplified or scaled-down.
Understanding the triple constraint theory
The triple constraint theory has been used in project management for over 50 years.
The theory argues that every project operates within the boundaries of three constraints:
Defined as the range, breadth, reach, spectrum, or dimension of the work to be done. Put differently, what work is being done and how much work is there?
Or the amount of time required to complete project tasks or the project itself.
Including resources related to labor, hardware, software, equipment, materials, and so on.
The triple constraint theory is a useful discussion point during client conversations.
Businesses use the theory to remind prospective clients that a project cannot be cheap, comprehensive, and fast at the same time.
In competitive industries where time is of the essence, it can also be used to set realistic expectations regarding cost and scope.
Additions to the triple constraint theory
While the theory has been a mainstay of project management for several decades, critics suggest that the three constraint model is inaccurate and impractical.
In response, the Project Management Institute (PMI) added a further three constraints:
What are the characteristics of the deliverable? Is it functional? Does it satisfy the needs or expectations of the stakeholder?
In the context of triple constraint theory, quality is a highly subjective term.
A new piece of software could have less functionality than was formally agreed upon and still be a success.
However, a car manufacturer that decides against its vehicles offering air conditioning will not be associated with quality by consumers in hot climates.
A significant factor in project management.
How does the business identify, analyze, and respond to risk? What level of risk is the project team willing to endure?
Establishing a project risk tolerance level then becomes one of the six constraints.
Represented by the value the project is expected to deliver to the organization and end-user.
If a project will not deliver benefits, then it should not be started.
If a project deliverable such as revenue falls below a predetermined limit, then the project should be stopped.
Here, the constraint is the point at which the business no longer deems the project viable.
- The triple constraint theory argues that every project is constrained by three inter-related factors: time, cost, and scope.
- The triple constraint theory is a useful way to keep client expectations in check during the consultation process.
- Some argue that the triple constraint theory is outdated and irrelevant for modern businesses. In response, three more constraints (quality, risk, and benefit) were added to the theory by the Project Management Institute.
Read Next: SWOT Analysis, Personal SWOT Analysis, TOWS Matrix, PESTEL Analysis, Porter’s Five Forces, TOWS Matrix, SOAR Analysis.
Read Next: Portfolio Management, Program Management, Product Management, Project Management.
Connected Management Frameworks
Project Management vs. Product Management
Read Next: Change Management.
Main Free Guides: