Assumptions: Your Get Out of Jail Free Card?
"The worst mistake of first contact, made throughout history by individuals on both sides of every new encounter, has been the unfortunate habit of making assumptions. It often proved fatal."
-David Brin
"What a man believes may be ascertained, not from his creed, but from the assumptions on which he habitually acts."
-George Bernard Shaw
You must stick to your conviction, but be ready to abandon your assumptions.
-Denis Waitley
I really enjoy quotes if you haven't already ascertained that fact. Above are three quotes about assumptions that I really enjoy and hit the mark-especially from the project management perspective.
What exactly is an assumption? And no, it is not when someone is making an a$$ out of you and me (ass-u-me). From the PMI perspective, the PMBOK defines an assumption as "factors that, for planning purposes, are considered to be true, real, or certain without proof or demonstration." From this definition, how do you believe we should use assumptions on a project? Let me start by defining what assumptions are NOT.
Assumptions are not:
- "Get out of jail free" cards
- To be used to cover your backside, otherwise known as CYA...cover your "activities", yes that's it...activities.
- To be stated and forgotten
Assumptions are believed to be factual. On projects, assumptions are made because we have unknown information or inconclusive data. They allow us to move forward on the project for planning purposes. That's why it's so very important to list and document our assumptions. Assumption analysis is nothing more than documenting assumptions, testing them for validity (iteratively until they're proven correct or incorrect), and identifying risks associated with each.
Not validating assumptions can result in disaster. Here's an example. In 1999, the NASA Mars Climate Orbiter mission ended in disaster when the orbiter crashed to the surface of Mars, destroying a $125 Million taxpayer purchased scientific instrument. The assumption, made by a contractor design team, was that English engineering units were being used for calculations. But, the NASA engineering team was using Metric units. A simple validation would have prevented an engineering catastrophe.
There are hundreds of examples of unvalidated assumptions in my career alone. I've learned, occassionally the hard way, that lessons not learned tend to repeat themselves until they are learned. Practice assumption analysis on all your projects. Test them for validity and periodically challenge them throughout your projects. You will be amazed at what you may discover.

