Method library · 48 methods
Problem-solving and quality methods
Forty-eight field-tested methods to state a problem precisely, contain it, find the proven root cause and make sure it never comes back — from Is/Is-Not and the 5 Whys to FMEA, SPC, 8D, DMAIC and A3.
Ready-made playbooks
Quality alert: the first 24 hours 1 day
One day to take control of a fresh incident: make safe, protect the customer, block every suspect lot, keep the evidence intact and pin down where the problem is — and is not.
Chronic scrap reduction month 1 month
One month against a loss everybody has learned to live with: count at the source, rank the losses, split the data, list the causes and prove the real one before spending money.
Customer complaint closure 4 weeks
Four weeks to answer a complaint the way customers expect: a structured 8D, a clean problem statement, causes of occurrence and escape, an error-proof fix and deployment to sister lines.
Process stability review 2 weeks
Two weeks to find out whether a disputed characteristic is a measurement, stability or capability problem — and to lock the answer into the control plan.
Major breakdown investigation 1 week
One week after a trip, a leak or a critical equipment failure: rebuild the sequence, map the failure combinations, dig to the cause, choose strong barriers and record the lesson.
One-page improvement cycle 3 weeks
Three weeks for a local problem owned by a team leader: see it on site, tell it on one A3, choose the countermeasure openly, pilot it and make it the new standard.
All 48 methods, by stage
State
Describe the problem as a measurable gap — no cause, no culprit, no solution yet.
- Is / Is-Not AnalysisFor each dimension — what, where, when, how much — write where the problem is and where it could be but is not. The…
- 5W2H QuestioningAnswer seven plain questions — what, who, where, when, why, how, how much — to turn a vague complaint into a factual…
- Deviation StatementWrite one sentence: object, defect, expected value, observed value, since when. No cause, no culprit, no solution…
- SIPOC ScopingMap suppliers, inputs, process steps, outputs and customers on one line to agree where the problem lives — and where…
- Closure Criteria FirstBefore any analysis, agree the measurable result and the observation period that will allow you to declare the problem…
Contain
Protect people, the environment and the customer while the real fix is found.
- First-Hour Incident ProtocolA fixed sequence for the first hour: make safe, stop the spread, preserve evidence, inform, appoint a leader. Thinking…
- Immediate Containment ActionsProtect the customer now with temporary barriers — extra inspection, sorting, a manual check — while the real fix is…
- Suspect Lot QuarantineTrace every lot made since the last known good one, block it physically and in the system, and define the clean break…
- Evidence PreservationKeep the failed part, the sample, the logs and the settings exactly as found — tagged, photographed and stored before…
- Andon and Escalation RulesGive every operator the right to signal an abnormality, and fix who responds, within how many minutes, before it…
Observe
Go where the problem happens and collect facts, counts and timelines — not opinions.
- Gemba WalkGo to the place where the work happens, watch the real process, ask open questions and write down what you see — not…
- Fact–Opinion SortTag every statement on the board as measured fact, observed fact, assumption or opinion — then go and check the…
- Check SheetDesign a simple tally form — defect type by time, machine or location — that operators fill in at the source with one…
- StratificationSplit the data by shift, line, operator, supplier, raw-material lot or product — a flat average often hides one guilty…
- As-Is Process FlowchartDraw the process as it really runs today — with loops, workarounds and waiting — by walking it with the people who do…
- Event Timeline ReconstructionRebuild minute by minute what happened before the failure from logs, historian data, shift notes and witnesses — and…
Root Causes
List the possible causes, dig down the chains and prove the real one before acting.
- Ishikawa DiagramPlace the effect at the head of a fishbone and list possible causes along families — method, machine, material…
- 5 WhysAsk “why?” again and again from the verified symptom, checking each answer with facts, until you reach a cause you can…
- Three-Path WhysRun three separate why-chains: why it occurred, why it was not detected, and why the system allowed both. Each path…
- Fault Tree AnalysisStart from the undesired top event and break it down with AND / OR gates into the combinations of failures that can…
- Change AnalysisList every difference between the problem case and a comparable good case, then every change around the date it…
- On/Off Cause VerificationProve the suspected cause by switching it on and off under control: the defect must appear and disappear with it.
Quality Tools
The statistical and risk tools of industrial quality: Pareto, SPC, capability, measurement, FMEA.
- Pareto AnalysisRank defect categories by frequency or cost and plot the cumulative curve: attack the vital few that make most of the…
- Scatter DiagramPlot pairs of values — temperature against viscosity, speed against scrap — to see whether two variables move together…
- Control Chart (SPC)Plot the process over time with limits calculated from its own variation, to tell common-cause noise from special…
- Process Capability Cp/CpkCompare the natural spread of a stable process with the tolerance: Cp says whether it can fit, Cpk whether it is…
- Gauge R&R StudyHave several operators measure the same parts several times to see how much of the observed variation comes from the…
- Failure Mode and Effects AnalysisFor each function or process step, list how it can fail, the effects and causes, rate them, and act on the highest…
Solutions
Generate countermeasures that act on the cause and choose between them openly.
- Brainwriting 6-3-5Six people each write three countermeasure ideas in five minutes, then pass the sheet on and build on what they read …
- TRIZ Contradiction MatrixState the conflict — improving one parameter degrades another — and look up the inventive principles that resolved…
- Hierarchy of ControlsRank each countermeasure from strongest to weakest — eliminate, substitute, engineer, organize, protect or inform — and…
- Weighted Decision MatrixAgree criteria and weights first, then score each option against each criterion: the choice becomes a visible…
- Pugh Concept SelectionCompare each concept with a reference solution, criterion by criterion, as better, same or worse — then combine the…
- Risk–Benefit GridPlace each candidate solution on two axes — expected benefit and implementation risk — to separate quick safe wins from…
- Potential Problem AnalysisBefore launching the chosen solution, ask what could go wrong with it, what would cause that, and prepare preventive…
Act
Plan, pilot and run the fix — with owners, dates and a structured roadmap.
- Action Plan with OwnersOne line per action: what exactly, linked to which cause, one named owner, a due date and a status everyone can read at…
- Pilot Run with Go/No-GoTry the countermeasure on one line, one shift or one tank, with success criteria and a rollback plan written down…
- PDCA CyclePlan a change on a hypothesis, do it small, check the result against the prediction, then act: standardize it or start…
- A3 ReportTell the whole problem-solving story on one A3 sheet — background, current state, goal, causes, countermeasures, plan…
- 8D MethodEight disciplines from team to recognition — including containment, verified root cause, permanent fix and prevention …
- DMAIC RoadmapDefine, Measure, Analyze, Improve, Control: a data-driven project roadmap for chronic variation problems whose cause is…
Sustain
Verify the result, lock it into standards and spread the lesson so it never comes back.
- Effectiveness CheckCompare the indicator before and after the countermeasure over the period agreed at the start, and close only if the…
- Poka-YokeDesign a device that makes the error impossible or immediately visible — a keyed fitting, a sensor that stops the…
- 5S Workplace OrganizationSort, set in order, shine, standardize, sustain: a workplace where abnormalities — leaks, missing tools, wrong parts …
- Standard WorkWrite the current best way to do the task — sequence, key points, reasons, timing — so the fix becomes the new normal…
- Control PlanFor each critical characteristic, fix what is checked, how, how often, by whom, and the reaction plan when it drifts …
- Horizontal Deployment (Yokoten)Copy the proven countermeasure to every similar machine, line, product or site where the same cause could strike — and…
- Lessons Learned RegisterTurn each closed problem into a short, searchable record — symptom, cause, fix, where it applies — and feed it into…