The methods covered one by one in these notes — DMAIC, Pareto, Ishikawa, CTQ, Six Sigma — all hang from one umbrella concept: operational excellence.
The short definition: a management approach that continuously improves processes, removes waste, increases value for the customer, and is set up not as a project but as the way work is done. It has no finish line; it has levels of maturity.
First, one piece of confusion
In capitals, OPEX (Operational Excellence) is the management approach. In mixed case, OpEx (operational expenditure) is a cost line: rent, salaries, energy, maintenance.
A well-run OPEX effort is expected to reduce OpEx, but the two are not the same thing. Both often come up in the same meeting; saying which one you mean at the start saves time.
The main methodologies
- Lean. Treats every step the customer would not pay for as waste, and aims to smooth the flow. Value stream mapping, 5S, standard work and visual management are its tools.
- Lean Six Sigma. Combines Lean’s flow and waste approach with Six Sigma’s statistical problem solving. Useful where a process has both speed and variability problems.
- Total Quality Management (TQM). Treats quality as the responsibility of the whole organisation rather than one department. One of the oldest approaches behind the cultural groundwork of OPEX.
- Continuous improvement (Kaizen, PDCA). Small but regular steps turning into a habit. It can be thought of as a subset of Lean.
- Business process management (BPM). Modelling, measuring and digitising processes end to end. It strengthens the structural side; it makes no claim to create culture.
These are not alternatives to each other. In practice Lean carries the framework, DMAIC the problem-solving discipline, Pareto the prioritisation and Ishikawa the root cause work.
Where to start
- Senior management takes ownership. Not by approving a budget, but by going to where the work happens, seeing the process first hand, and creating a setting where mistakes are not punished.
- The current process is mapped. Steps, waiting times, approvals and rework become visible. Waste that cannot be seen cannot be improved.
- One area is chosen. One cell, one material group, one process. Efforts that start with the whole plant mostly stall in the second month.
- Measurement is set up. Draw the baseline before the improvement; otherwise you end with “it got better” and nobody able to say by how much.
- The gain is tied to a standard. Unless the new way is fixed as an instruction, a field, a requirement or a control step, the old way comes back.
Which indicators are tracked
- First-time-right rate
- Lead time (order to delivery)
- Change in unit cost
- Customer complaints and recommendation scores
- Number of employee suggestions implemented, and the time taken to close one
- OEE, revenue per employee, labour hours per unit
One rule: a cost indicator is never tracked on its own. An effort that chases inventory turns alone can look “successful” while quietly breaking delivery performance. Always put a service indicator next to the cost one.
Where it most often comes apart
The work starts, the board goes up on the wall, and six months later the process is back to what it was. The reason is usually not the method, but that the improvement has no counterpart in the system: measurement lives in Excel, the new standard has no place on the screen, and the rule stays in one person’s memory.
We covered this in detail in Operational Excellence Starts on the Floor and Survives in the System.
How we run it
We carry out process analysis and improvement work under Process Consulting. We take indicators out of hand-filled forms and make them permanent on ErpwareBI; where two systems have to move data between them, the Integration Studio steps in. When the new standard needs a screen of its own, we design it with erpware Builder.
For the definition and the list of methodologies: Yalın Enstitü (Turkish Lean Institute), Operasyonel Mükemmellik (OPEX) Nedir? Nasıl Elde Edilir?