Knowledge Base · Critical Thinking
How do I challenge an assumption my team treats as fact?
Ask for the evidence behind it and what the team has not considered, then test the smallest version of the doubt. Chapter 9 of the book treats assumption-challenging as a core thinking skill and shows an operator-error assumption, acted on with a formal warning, collapsing under four Whys into an outdated maintenance schedule.
Every team runs on assumptions: the report nobody reads is vital, the customer wants the cheapest option, the form needs all fourteen fields. Chapter 9 of the book teaches challenging assumptions as a core critical-thinking skill, and its servant-leader example is pointed: teams will only question the obvious when the leader's questions and humility make it safe to do so.
The book's Rule of Three gives the challenge a polite, repeatable form. Ask what evidence we have: is this assumption based on data, or on something that was true three years ago? Ask what we have not considered: whose experience contradicts it, and have we asked them? Assumptions hate those two questions, because most of them survive on never having been asked either.
The factory story in the same chapter shows the stakes. Operator error was an assumption treated as fact, complete with a formal warning issued. Four Whys later the real cause, an outdated maintenance schedule, was found. The assumption had not just been wrong; it had nearly cost a good employee his standing while leaving the fault in place to jam again.
Make the practice routine rather than heroic. Once a month, ask the team to name one thing we all believe about our process that we have never tested, and run the smallest possible check on it, a PDCA cycle on a belief. The book's promise underneath the habit: a culture where assumptions are routinely examined is hard to surprise, and very hard to keep stuck.
Related questions
- What is the Rule of Three for asking better questions?
- What does a 5 Whys look like on a machine breakdown?
- How do I lead a blameless post-mortem?
Source: Continuous Improvement in the Workplace, Ch. 9 (Harnessing the Power of Critical Thinking).