Every day, FAA's Air Traffic Organization (ATO) services more than 45,000 flights and 2.9 million airline passengers. (Federal Aviation Administration, United States Department of Transportation, April 10, 2023, https://www.faa.gov/air_traffic/by_the_numbers, accessed January 15, 2024.)
How many people would fly if they knew that there would be 450 short or long landings (“defects”) at major airports every day?
This number is shocking. Yet, it reflects a 99% quality yield.
Is this good enough?
Defects
Defects are defined as anything that does not meet and is unacceptable to the customer’s requirements. Defects are one of the main Lean categories of waste, and occur when products are not up to standard and must be fixed before they can be sold.
I’ve been asked what is an acceptable quality yield rate and I always answer 100%. More times than not I’ve received exclamations of something like, “That is impossible to achieve!”
In truth, with the current state of the culture and mindset, it may seem impossible. The expectations of customers come into play, too.
A curious question to ask is are your business systems producing “good enough” to be considered perfect by your customers? If not, begin looking more closely at the defects these systems are producing, as well as excessive deviations.
Going back to the airplane landing example, I doubt any reasonably-minded person would say 99% is good enough. This leads us to the topic of Lean Six Sigma.
Lean Six Sigma
Lean Six Sigma is a systematic and collaborative data-driven approach to process improvement and combines principles from Lean and Six Sigma methodologies.
It aims to optimize processes, improve productivity, enhance efficiency, minimize waste, and reduce defects, which translates into bottom-line cost savings, profit improvements, increased competitive advantage, and greater customer satisfaction.
Using Lean Six Sigma as a guide, you can measure your current performance in defects per million opportunities and set a goal of reaching the next level of sigma, such as level 5 sigma, estimating it will take 18 to 24 months per step.
Why should we strive to reach a Six Sigma level of performance quality?
It is simple.
In many industries and process outputs, “99 percent good” can fall considerably short of customer expectations.
Historically, most companies operate between 2 and 4 Sigma levels (Nexus at Michigan College of Engineering, What is Six Sigma?, Donald P. Lynch, Ph.D., https://nexus.engin.umich.edu/wp-content/uploads/2021/11/Nexus_WhatIsSixSigma_Whitepaper.pdf, accessed January 15, 2024.)
Sigma Levels
At a sigma level between 2 and 4, they are applying fundamental quality tools. They may have formal quality systems established. But they are not experiencing the quality improvement they desire to decrease defects and move up to the next sigma level.
Companies are typically stuck at a certain level because of several potential issues, including:
Dependence on inspection and rework
Reliance on trial-and-error methods of problem-solving
A culture of fire-fighting
Minimal focus on in-process quality measurements
The absence of a team-based environment that fails to foster collaboration
Break Through to a Higher Level of Quality Performance
To break through to a higher level of quality and sigma performance, companies need to change their culture to one that:
Values a high level of process improvement knowledge
Is open to challenging the status quo
Has conviction in the opportunity to improve with a belief in the Six Sigma methodology
It is necessary to have personnel dedicated and driven to process improvement, with the business providing them with the new skills, tools, and information they need to make a difference.
1% Matters
What sigma level is your company operating at? You can find this out by using sigma level calculators easily accessible online.
Short or long airplane landings per day at 99% yield equals 450 at a sigma level between 3 and 4.
Operating at a 6-sigma level short or long landings decrease to 0.153 per day.
What a difference 1% makes.