Inverted Triangle

Definition

The Inverted Triangle is a constraint model showing that in adaptive projects, time and budget are fixed while scope is variable. This is the inverse of predictive projects, where scope is fixed and time/budget absorb change. When unexpected changes occur in an adaptive project, the response is to adjust what is delivered (scope/backlog), not when or for how much. The product owner makes these trade-off decisions through backlog prioritization.

Related concepts

• Adaptive Development Approach
• Scope Domain
• Backlog Management
• Predictive Development Approach

Exam angle

• Adaptive context only: the inverted triangle applies to adaptive/agile projects — wrong answers apply it to predictive scenarios
• Trade-off decision owner: in adaptive, the product owner decides what to cut or defer when constraints are hit — not the PM, not the team
• Budget overrun in adaptive: wrong = expand scope to justify the budget; right = the budget constraint means you deliver less scope, not that you add more

My notes