In practice, however, trading between constraints is not always possible.

In fact the scope can be a function of cost, time and performance, requiring a trade off among the factors. It is understood that the area of the triangle represents the scope of a project which is fixed and known for a fixed cost and time. Later, he expanded quality with performance, becoming CTQ. Martin Barnes (1968) proposed a project cost model based on cost, time and resources (CTR) in his PhD thesis and in 1969, he designed a course entitled 'Time and Cost in Contract Control' in which he drew a triangle with each apex representing cost, time and quality (CTQ). Choose two.' as stated in the Common Law of Business Balance (often expressed as 'You get what you pay for.') which is attributed to John Ruskin but without any evidence and similar statements are often used to encapsulate the triangle's constraints concisely. Cutting budget without adjusting schedule or scope will lead to lower quality. Similarly, increasing scope may require equivalent increases in budget and schedule. Changes in one constraint necessitate changes in others to compensate or quality will suffer.įor example, a project can be completed faster by increasing budget or cutting scope.The project manager can trade between constraints.The quality of work is constrained by the project's budget, deadlines and scope (features).While its origins are unclear, it has been used since at least the 1950s. The project management triangle (called also the triple constraint, iron triangle and project triangle) is a model of the constraints of project management.

Project triangle strategy platforms