The iron triangle is a project management axiom where there are three key constraints on a project1: - scope the work that needs to be completed for a project - time to get done (the deadline) - resources the people and tools to complete the project
You can’t change one without changing the others.
Pick Two
A common refrain is: faster, cheaper, quality: pick two. Kent Beck adds to this to include “more”, or an expansion in scope2. He anchors on quality being a constant so you get:
- Better/Sooner/Cheaper - Spiking to get better feedback (Exploring)
- Better/Sooner/More - Deliver features quickly without constraining cost (Expand)
- Better/Cheaper/More - economically deliver features for the long run (Extract)
1. Stanier, J. Parkinson’s Law: It’s Real, So Use It. https://theengineeringmanager.substack.com/p/parkinsons-law-its-real-so-use-it (2024).
2. Beck, K. Better/Sooner/Cheaper/More. https://tidyfirst.substack.com/p/bettersoonercheapermore (2022).