Six Sigma and DMAIC

Developed at Motorola, spread by General Electric · 1986

Reduce variation until defects are rare, working through a fixed five-step cycle with the measurements agreed up front.

Its place in the frameworkBusiness Core›Manufacturing Operations

What it does

Define the problem, measure what is actually happening, analyse the causes, improve the process and control it so it does not drift back. The last step is the one that distinguishes it: most improvement efforts stop at improve, and the gain quietly disappears over the following year.

Reach for it when: Where a process runs often enough to be measured and the cost of defects is real.
Where it stops: It improves processes that already exist and rewards consistency, which is why organisations that push it hardest often become slower to try anything new. It also needs data most small operations do not have.

Developed at Motorola by Bill Smith from 1986; adopted at General Electric from 1995.

Why it sits at Manufacturing Operations

Where things are actually made — capacity, flow, quality and the maintenance that keeps all three possible. Applies wherever the organisation produces rather than only assembles.

A model is only useful when you reach for it at the right moment. This one answers a question that arises here — so it is filed here, and nowhere else. These are the working areas it serves:

Capacity planningGoldratt’s theory of constraints: identify the constraint, exploit it, subordinate everything else to it.
Production flowLean manufacturing and value stream mapping, which separate processing time from the far larger waiting time around it.
Quality managementStatistical process control and the quality management tradition from Deming and Juran on prevention over inspection.
MaintenanceTotal productive maintenance, and overall equipment effectiveness as the combined measure of availability, performance and quality.

All of Manufacturing Operations

What it touches elsewhere

Nothing in a business is decided on its own. A conclusion reached with this model at Manufacturing Operations lands in these other cores, whether or not anyone follows it there.

Business CoreProduction runs on assets, and the supply chain feeds it.
Goal CoreCapacity is a hard limit on what any growth goal can promise.
Data CoreYield, throughput and equipment effectiveness are among the most instrumented measures in any business.
Time CoreChangeovers, maintenance windows and lead times are all timing decisions.

Filed at the same place

These answer questions that arise at Manufacturing Operations too. Where they disagree with this one, the disagreement is the useful part.

Overall equipment effectivenessOne number combining how much of the time equipment runs, how fast, and how much of what it makes is good.
Value stream mappingDraw the whole path a product takes, with the waiting included, and the waiting turns out to be most of it.

Elsewhere in Business Core

These are other people’s models, named here so you can go to the source and use them properly. The Omnigoal is not affiliated with their authors and is not endorsed by them; nothing of theirs is reproduced here — no canvas, no diagram, no wording. Each is described in our own words, with the originator credited, because the framework is a place to put thinking, not a replacement for the people who did it. Model names and trademarks belong to their respective owners and are used here only to refer to the work itself.

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