Iron Triangle
Table of Contents
Scope, time, and resources trade against each other - name which leg you sacrifice instead of pretending all three flex.
Key Concept
- Iron triangle means scope, schedule, and resources constrain each other - improve one, pay on another.
- Scope Is a Promise and Cost of Delay are the two legs PMs argue about most with stakeholders.
- Pretending you can add scope, hold date, and skip headcount is how projects lie politely until they fail loudly.
Level 1 - Recognize
Iron triangle means scope, time, and resources trade against each other - you cannot max all three.
Level 2 - Explain
Like a triangle stool - push one leg longer and another must shorten or the seat wobbles.
Level 3 - Use
On the next change request, write which leg moves - cut scope, add people, or slip date - before anyone leaves the room.
Level 4 - Connect
There Is No Perfect Solution accepts tradeoffs; Decision Quality checks the choice still holds after sleep.
Level 5 - Create
Put the triangle on one slide per major initiative - Steering With a Chart before the public yes.
Examples
- Glad we named extra headcount or a two-week slip when legal added review - triangle on paper beat a heroics speech.
- Stakeholder wanted all three portals by Q2 with the same team - we cut scope to one portal; triangle forced an honest pick.
Note Relationships
| Relationship | Wikilink | Reason |
|---|---|---|
| extends | PM Mindset | Constraint model inside the hub |
| extends | Scope Is a Promise | Scope leg of the trade |
| extends | Cost of Delay | Time leg of the trade |
| extends | Steering With a Chart | Triangle belongs on the chart |





