Short answer
A target number from a sponsor is a starting point, not a diagnosis. The job of the Define phase is to verify the data, establish what actually needs to improve, and turn the expectation into a concrete, fact-based problem, scope and action plan.
"We need to get OEE to 85%"
How many times have I heard that? A sponsor arrives with a number — specific, ambitious, often benchmarked against another plant or an industry figure. That's exactly where my role begins — and the most important phase of any project: Define.
Why a target number isn't a problem yet
"OEE 85%" says where the company wants to be. It doesn't say what isn't working today, why OEE sits where it does, or which losses — availability, performance, quality — carry the most weight. A team that jumps straight into action without that answer usually hits a symptom, not a cause. The result: plenty of activity, little lasting result.
What actually happens in Define
This is where we establish what the team should actually work on. In practice, it always comes down to the same four elements.
Data verification. Is OEE even calculated consistently across all lines? Is the source data reliable, or is it a manual log with a gap from reality? Skip this step and the rest of the project stands on shaky ground.
Problem definition. A specific statement: which process, which metric, what gap against the target, since when the problem has existed, and its scale.
Scope. Which lines, shifts, products or sites are covered by the project — and, just as important, what's deliberately left out.
Goal. Measurable, time-bound, and clearly tied to a business result, not a general slogan.
Splitting the roles: sponsor and project team
The sponsor says what they expect — and that's exactly the sponsor's role. They know the business context, know why the topic is a priority, and hold the mandate to allocate resources.
Our role — as project lead and team — is to establish what actually needs to improve and how to get there. Not based on assumptions or beliefs, but on data verified on the gemba. That distinction protects the project from the most common failure: solving a problem no one ever precisely defined.
From expectation to action plan
A well-run Define phase ends with a project charter the team and sponsor can return to throughout the project: a clearly defined problem, scope, goal, business case and priorities. Only with that document in hand do we go back to the sponsor with a concrete, fact-based proposal for action — instead of a promise built around a number no one can yet explain.
This is exactly where it's decided whether the following phases — Measure, Analyze, Improve, Control — will work on the right problem. A mistake made in Define is the cheapest to fix right now, at the start. Later, it costs the most.
Author
Andrzej Smoleński — production and operations transformation manager, Lean Six Sigma Master Black Belt. More than 20 years of experience developing processes, teams and management systems.