Are untested assumptions the most dangerous aspect of projects? They can cause projects to fail. Let's ban them.

What Are You Assuming?

I remember attending a 3-day strategic planning conference where my role was to sum up what had been said and decided in the conference. When I pointed out that I had sat through 22 hours of presentations and discussions and not heard the word ‘Customer’ once, I was told, “The customer was always assumed!” No they weren’t, they were ignored.

“Assumed” — is this the most dangerous thing on projects? People ‘assume’ that the project will enable the benefits. People ‘assume’ the GM who signed off the project fully understands it and its potential ramifications. People ‘assume’ the new product will sell in the market even though they’ve not identified why the market will want to buy it. And so on.

The Cost of Assumptions

Assumptions can speed things up in the short term, but dramatically reduce value in the long term.

A recent project team ‘assumed’ that the software could do what they wanted, bought it, installed it and then found it couldn’t. $3.4m investment for zero return.

Another project team and Sponsor could not answer any of the questions as to why anyone would buy their new product. They ‘assumed’ it would sell because other (different) products had sold.

In Conclusion

TOP has declared war on assumptions as shortcuts and insists the work be done so that the true facts, outcomes and realisable value are known and delivered. This insistence on reality routinely shortens the duration of projects as less time is spent on rework correcting false assumptions.

TOP avoids misaligned expectations, mistaken purchases and missed benefits.

Whenever anyone says, “We assume …” the red warning lights should go on.

Let’s stop spending millions of dollars on the basis of untested assumptions. Instead let's start spending our dollars on the basis of validated business cases.

Topics: Project Controls

Further Reading



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Revision History

First published: Simms, J. (Apr 2008) as "Assumptions - The Most Dangerous Aspect Of Projects?"

Updated: Chapman, A. (March 2020), Revisions and Corrections