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
PSV-01 · Continuous improvement
5 Whys — Problem Solving
Deepens a causal chain through successive questions, distinguishing symptom, probable cause, root cause, containment, countermeasure and recurrence prevention.
5 porquês · causa raiz · contenção · contramedidaFormulários 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.
PSV-01Which causal chain explains the problem, and at which link is there enough evidence to justify a countermeasure?
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.
Analysis tools require discipline to avoid turning the first plausible explanation into a cause. Start with facts, formulate hypotheses and seek evidence that can support or refute each interpretation.
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.
The conclusion must be traceable to the reasoning. If a third party cannot understand why the decision follows from the recorded evidence, the analysis needs to be strengthened.
03
WORKED EXAMPLE
How the method behaves in a real situation.
Shipping delay → picking started late → list released late → orders waited for manual review → credit rule held cases without exceptions. The team measures how many orders are unnecessarily held before changing the rule.
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.
01evidence per link
02cause frequency
03% cases explained
04countermeasure effect
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.
Widely used management heuristic. Useful for structuring decisions, but not by itself a causal model or scientifically validated scale.
Five is not magic. Stop when the cause is at a testable, controllable level; do not force five answers or accept opinion as cause.
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.
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.