Continuous Improvement
What this domain tests
Continuous improvement tests structured problem solving and sustained change: PDCA, DMAIC, Lean, 5S, kaizen, value-stream analysis, root cause tools, standard work, and maturity. The exam values a defined problem, measured baseline, and verified sustainment.
Core rules and concepts
- Define the problem in measurable terms: what, where, when, how much, and impact. Avoid solution-first thinking.
- PDCA and DMAIC provide discipline: define, measure, analyze, improve, control.
- Lean removes waste: waiting, overprocessing, motion, transport, inventory, defects, and overproduction.
- 5S creates a stable workplace: sort, set in order, shine, standardize, sustain. The fifth S is the hardest.
- Root cause tools include 5 Whys, fishbone, and failure analysis. Validate causes with data.
- Standard work and visual management sustain gains. Without them, improvement decays.
- Maturity models help sequence improvement, but the exam favors specific measurable gains over labels.
Worked example
A line changeover takes 95 minutes; the target is 45. Observation shows 30 minutes of internal setup while the machine is stopped, 20 minutes of searching for tools, and 15 minutes of adjustment trials. Using SMED logic, the team converts tool search and preparation to external setup, standardizes the tool cart, and creates a first-article checklist. Internal setup falls to 35 minutes, searching disappears, and trials fall to 10 minutes-new changeover 45 minutes. The reasoning: separate internal from external work, then simplify what remains. Results are verified with five timed changeovers and a standard work sheet.
Traps that cost marks
Choosing a tool before defining the problem. Claiming improvement without a baseline. Skipping the control phase. Celebrating a pilot that is not standardized. Using 5S as a cleaning campaign. Blaming people when the process is unstable.
Exam tip
When two improvement options appear, choose the one that defines the problem, measures the baseline, and includes a sustainment mechanism.