The Six Sigma process is a logical, scientific process that often draws .. well, logical, scientific people.
However, not all project sponsors are what we would consider logical. Or scientific. Or maybe we just don’t understand nor agree with their viewpoint.
Here’s a case from a reader that reached out.
” I am trying to find documentation that a 1.4% frequency rate would be considered infrequent. Obviously to a logical mind this seems infrequent but i am not dealing with a logical entity ”
– Lori.
I did ask Lori to follow up with more context. But let’s see what we can do here.
If you are talking about the output of some process – and by Lori’s writing I’m guessing she’s trying to illustrate that some undesirable outcome (a defect, failure, etc) at a rate of 1.4% is infrequent.
Ignoring that a process operating at a Six Sigma level gives only 3.4 defects per million opportunities – a rough success rate of 99.99966% – or a defect rate of 0.00034%, my first question would be ‘Infrequent compared to what?’
Usually, a question from a sponsor in the form of “How infrequent is infrequent?” or “Is the rate you’re showing me infrequent?” can really be boiled down to something simpler. It’s the human question of “How do I know what you’re suggesting to me is right?”
Fortunately, Lean Six Sigma gives use very logical tools to help us illogical humans sort through our options. Let’s look at a few.
Benchmarking
One such tool is Benchmarking. If you need to determine where on the spectrum your process exists, you could benchmark it against something else.
For example, based on external sources (like news), one might feel that gun related homicide is frequent (not saying it is or not, just an example.) But when charted vs other forms of preventable death (eg heart disease) that rate might be seen as relatively infrequent.
Cost of Poor Quality – And the Cost of Quality
Another option, and I know as I type this I’m going to get flack from those impractical, ivory-tower, Six Sigma purists out there, is…. Not everything has to be at a Six Sigma Level!
Shocker, I know!
The only business reason to pursue a Six Sigma level of quality is to advance the bottom line.
Sometimes you need to have that level of quality to make the margins of a business work – it’s simply too expensive to operate in any other manner.
Sometimes it’s a Critical to Quality issue where a client simply will not deal with you without a certain level of quality.
Sometimes the juice isn’t worth the squeeze! (Or, in other words, it’s too expensive to have impeccable quality.)
All of these eventualities can be illustrated with sample cost-benefit analysis tables, the same basic cost-benefit framework used well outside of Six Sigma.
Stakeholder Analysis
Before you can win an argument with a sponsor, it helps to understand what they actually care about, which is rarely the statistic itself. A quick stakeholder analysis (what does this person actually need to see to feel confident, and what have they been burned by before) often reveals that “1.4% feels high to me” really means “the last time someone told me a rate was low, it caused a problem I got blamed for.” Address that underlying concern directly, with a concrete monitoring plan or a smaller pilot, and the statistical argument becomes much easier to land.
A Sports Angle
A baseball analogy that tends to land with skeptical sponsors: a .990 fielding percentage sounds excellent until you remember that’s still roughly one error every 100 chances, and in a sport played at the highest professional level. Whether a given error rate counts as “good” always depends on the benchmark you’re comparing it to, exactly the same question Lori’s sponsor was really asking, just dressed up in statistical language instead of sports language.
A Fault Tree for the Truly Skeptical
If a sponsor’s real objection is “I don’t believe this failure rate matters,” a fault tree analysis can help by working backward from the actual consequence (a safety incident, a customer loss, a compliance violation) to show exactly which combination of failures would have to occur together to produce it. Sponsors who dismiss a bare percentage often respond differently once they see the specific, concrete failure path that percentage represents, because a fault tree translates an abstract rate into a tangible scenario.
None of these tools replace a direct conversation, but they give that conversation something concrete to stand on besides raw statistics alone.
Frequently Asked Questions
What if the sponsor still won’t budge after all this? Sometimes the honest answer is that the decision genuinely isn’t yours to make, and a sponsor is weighing factors (office politics, risk tolerance, a past bad experience) you don’t have full visibility into. Document your recommendation and the data behind it clearly, make the ask once more with any new tool from this article, and then respect that the sponsor owns the final call on their own project.
Is it ever worth escalating past the sponsor? Rarely, and only when the stakes are genuinely high (safety, legal exposure, major financial risk). For most day-to-day disagreements about what counts as an acceptable defect rate, escalating burns more trust than it’s worth; better to keep building your case with the tools above.
Summary
If it feels like you’re working with an irrational entity try to step back and discover the question on the table that is really being asked. Emotion-based appeals backed by science can help win the day rather than pure logic.
Your Turn
What would you recommend to Lori? What tools would you see that could work in this space? Let us know in the comments below.