Define the system and unit of analysis
Specify process, population, product, time window, boundaries and aggregation level. Without a defined unit of analysis, measures and comparisons may represent different phenomena.
TECHNICAL GUIDE · STRUCKEL TOOLS
PDC-04 · Continuous improvement
Lean PDCA — Problem Solving
Combines PDCA discipline and Lean thinking to structure the challenge, root cause, containment, countermeasures, metrics, implementation and standardization.
PDCA · Lean · causa raiz · contramedidasFormulários Struckel
01
MANAGEMENT QUESTION
The problem the tool must make decidable.
Before opening a form, define the question that must be answered. A management tool is useful when it reduces ambiguity, exposes assumptions and makes clear which decision will be made from the evidence produced.
PDC-04Which abnormal condition should be understood at the gemba, which root cause explains the deviation, and which countermeasure changes the mechanism rather than the symptom?
Continuous improvement requires separating opinion from evidence and turning a broad problem into a sequence that can be observed, tested and revised. The tool creates value when it starts from an explicit current condition, applies criteria before concluding and ends with a verifiable decision — not merely a completed document.
Use it when you need to reduce variation, solve recurring problems, test changes, prioritize causes or preserve learning beyond the meeting in which it was produced.
02
METHOD ARCHITECTURE
Technical construction: from operational definition to evidence.
An improvement cycle creates temporal discipline: plan with a hypothesis, execute under control, observe effects and decide the next move. Closing the cycle should produce reusable knowledge, not merely confirmation that a task was completed.
Define criteria before evaluation
Translate abstract concepts into operational definitions, scales, classification rules and data sources. Criteria should exist before the result to reduce retrospective interpretation.
Preserve traceability
Link each conclusion to data, observations, assumptions and owners. When a score is used, retain its components; when a hypothesis is used, record how it will be tested.
Compare what was observed with what was expected. Record deviations, test conditions, data and the rationale to adopt, adapt, standardize or test again.
03
WORKED EXAMPLE
How the method behaves in a real situation.
A 45-minute average setup creates queues. Observation shows 18 minutes of internal work that could occur while the machine runs. The countermeasure externalizes tool preparation and tests median, dispersion and safety before revising standard work.
The example is intentionally specific. Numbers illustrate the reasoning and are not universal benchmarks: limits, scales and targets must be defined for the process being analyzed.04
MEASUREMENT AND INTERPRETATION
What to observe so the document does not become mere form filling.
Measures should serve reasoning. Whenever possible combine outcome, process and contextual evidence. For time series, look for patterns and variation rather than only point-in-time before/after comparisons.
01cycle time
02median and dispersion
03WIP/queue
04safety
05standard-work adherence
Consistency test
Ask whether another person, using the same definitions and evidence, would reach a similar interpretation. If the answer depends heavily on individual judgment, refine the operational definition, scale or data source.
05
LIMITATIONS AND GOVERNANCE
The tool supports decisions; it does not replace judgment, context and validation.
Established method/tool in professional and academic literature; exact implementation should be tailored to context.
“Root cause” should not mean the last answer in a 5 Whys chain. Require evidence linking cause to effect and countermeasure to mechanism.
Define an owner, review frequency, official data source and condition for reopening the decision. Link actions to deadlines and indicators, hypotheses to tests, and risks to treatment and follow-up.
DefinitionEvidenceInterpretationDecisionReview
06
METHODOLOGICAL BASIS
References for deeper study of the method.
The references below support the methodological family or principle used. Struckel’s digital implementation operationalizes application, documentation and traceability; it does not change the conceptual limits of the original sources.
OHNO
Ohno T. Toyota Production System: Beyond Large-Scale Production. Productivity Press; 1988.
LEI_A3
Open reference Shook J. Managing to Learn: Using the A3 Management Process to Solve Problems, Gain Agreement, Mentor and Lead. Lean Enterprise Institute.
MONTGOMERY
Montgomery DC. Introduction to Statistical Quality Control. Wiley.
USE IT IN PRACTICE
Turn the method into a document ready for real work.
Struckel Forms offers a free way to structure this methodology with guided fields, contextual help and print/PDF preparation. Use the tool to organize reasoning; use consulting when the challenge requires design, implementation, facilitation or executive follow-up.