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guide/english/software-engineering/iron-triangle-or-pick-two/index.md

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+---
+title: The Iron Triangle, or "Pick Two"
+---
+# The Iron Triangle, or "Pick Two"
+
+Software development is a series of tradeoffs between features implemented, the quality of the features, and how long it takes to produce.
+But, no matter how much effort is put in, one cannot sustainably maximize all three of these without increasing the cost of the project.
+For software development, often cost is directly related to the number of people assigned to and working on a project. 
+This concept is often summed up as "Pick Two: Quality, Speed, Features". 
+
+This relationship between quality, features, speed, and cost is illustrated by imagining a triangle with a fixed volume 
+with the volume being quality. 
+One can increase speed to implement and the features, but quality will suffer if cost is unchanged, 
+keeping the volume of the triangle the same.
+
+Frequently cost is assumed to be constant because in most cases the cost is fixed and there is no budget to add more people 
+nor are there people available for transfer from other projects.
+![Illustration of Iron Triangle with Scope, Resources, Schedule, and Quality](http://www.ambysoft.com/artwork/ironTriangle.jpg)
+
+----
+## Sources:
+* [The Broken Iron Triangle Anti-Pattern](http://www.ambysoft.com/essays/brokenTriangle.html) Classic essay by [Scott Ambler](https://en.wikipedia.org/wiki/Scott_Ambler)