"Six Sigma is a quality programme that, when all is said and done, improves your customer's experience, lowers your costs, and builds better leaders."
Jack Welch
Six Sigma: it sounds like something out of a Dan Brown novel. But it's not a mystery to be unravelled; rather, it is a defined, data-driven methodology aimed at process improvement and consistent output in manufacturing.
Although it was originally developed by Motorola in 1986, Six Sigma is more commonly associated with General Electric (GE). Jack Welch, the former chairman and CEO of GE, made Six Sigma a core component of his business strategy during his twenty-year tenure. It is now an entrenched business philosophy at the organisation.
Today, Six Sigma is utilised across industries. So, what does it involve and what does it look like in practice?
"In contrast with other quality initiatives, Six Sigma recognises that there is a direct correlation between the number of product defects, wasted operating costs, and the level of customer satisfaction."
Process Quality Associates Inc (PQA)
Six Sigma revolves around reducing errors, to deliver better products and services – thereby improving the customer experience and increasing profit. It's essentially a quest for perfection – although, of course true perfection is impossible to achieve.
The term "sigma" derives from the eighteenth letter of the Greek alphabet (Σ, σ, ς). A Six Sigma process is one in which 99.99966 per cent of products created are free of defects; to put it another way, there should be no more than 3.4 defects per million opportunities (DPMO).
A defect is anything that falls outside of a standard process – that is, a variation. And, in electronics manufacturing, this measurement can be used in relation to anything from a component to a period of time. These calculations are rooted in mathematics and statistics and are further explained here.
GE outlines the key concepts that inform Six Sigma as follows:
The successful deployment of Six Sigma is dependent on rolling it out across the entire organisation.
The two main sub-methodologies for Six Sigma are: DMAIC and DMADV (also known as DFSS (Design for Six Sigma)). Both approaches are data-driven: the former is used to improve current business processes, while the latter focuses on creating new processes or products. Often, a business might implement DMAIC and then move on to DMADV.
iSixSigma defines each methodology as follows:
DMAIC
DMADV
Six Sigma is deployed by a number of key people across an organisation, including:
This might all sound a bit complex and intimidating. However, it requires specialist training, in order to achieve success. There are a number of Six Sigma certification organisations, including professional associations, universities and for-profit training organisations.
More recently, Six Sigma has been combined with lean manufacturing to create a new methodology: Lean Six Sigma. Lean manufacturing is, of course, aimed at eliminating waste within manufacturing – and so the two complement one another well.
Lean is implemented to identify opportunities to decrease waste within the manufacturing process and then Six Sigma is used to decrease defects. Together, these two methodologies help to maximise customer satisfaction and profit.
Today, manufacturing firms exist in a challenging landscape. There is an increasing demand for customised products, which are expected to get to market faster than ever before - and, of course, the looming Fourth Industrial Revolution is disrupting the sector at its core.
Against this backdrop, it is more vital than ever to retain a competitive advantage. Implementing Six Sigma (and Lean Six Sigma) is an excellent way to ensure you remain on top.