Facilitator guide
Case objectives, demonstration plans, debriefs, common mistakes and application checks across all 81 workplace cases and method lessons.
Download Facilitator guide PDF · 166 pages · 65.1 MBProblem solving and verified change
Understand how the methods relate before selecting a detailed lesson.. Follow the visual, practise a decision, then check your thinking.
Fictional teaching examples and AI-generated illustrations. Proposed changes and goals are not achieved results. Use the written instructions and check local conditions before applying a method.
Move from a problem to verified learning
Protect people and customers when exposure requires an immediate response, while keeping containment distinct from permanent correction. Define the expected and actual condition before selecting a method. Different problems need different depth: an urgent restoration, a recurring gap, a target-condition experiment and open-ended innovation are not the same. Collect evidence using stable definitions and meaningful strata. Fishbone branches and why-chains organize hypotheses; they do not prove causes. Test alternatives, predict the effect of a countermeasure and verify relevant outcomes and unintended effects. Effective changes need ownership, learning and later review. An ineffective test should return the team to the evidence.
Follow the method
- Protect now: Contain immediate exposure when needed
- Define the gap: Expected versus actual in a stated scope
- Choose the approach: Match urgency, complexity and uncertainty
- Collect and separate: Operational definitions and meaningful strata
- Test explanations: Hypotheses, alternatives and discriminating evidence
- Try a countermeasure: Prediction and controlled test
- Verify the effect: Relevant outcome and unintended effects
- Standardize and revisit: Ownership, competence and later checks
Read the example carefully
A hypothesis map is not proof of root cause.
Containment may continue while causal investigation and validation proceed.
The method choice depends on the problem; the map does not require every problem to use every tool.
Try it before revealing the answer
A team’s fishbone contains many plausible causes. What makes it ready to choose a permanent action?
Reveal the answer and reasoning
It is not ready from the diagram alone. Choose discriminating observations or tests, examine alternatives and connect any proposed action to supported causal evidence.
Turn clues into discriminating causal tests
Useful evidence begins with a clear problem and stable operational definitions. Preserve denominators and time order, and stratify where populations or conditions differ. A Pareto comparison can prioritize a question on a declared basis; it does not prove a cause. Fishbone diagrams and why-chains help organize possible mechanisms and alternative explanations. A scatter relationship is another clue, not proof of causation. Choose an observation or test that would distinguish the alternatives. Retain contrary and incomplete evidence instead of forcing a neat story. Update the explanation only to the strength supported, and refine the problem scope when the evidence requires it.
Follow the method
- Operational problem: Expected, actual, where and when
- Collect consistently: Definition, denominator and time order
- Stratify the evidence: Separate relevant conditions and populations
- Prioritize the question: Magnitude, risk and declared comparison basis
- Map hypotheses: Fishbone or why-chain with alternatives
- Design a test: What observation would distinguish explanations?
- Observe the result: Preserve contrary and incomplete evidence
- Update the explanation: Supported cause or further investigation
Read the example carefully
Raw counts can mislead when exposure denominators differ.
A ranked category, correlation or fishbone branch does not establish causation.
A why-chain may branch; stop where evidence stops instead of inventing a fifth answer.
Try it before revealing the answer
One shift has more defects but produces ten times as many units. What should be checked before blaming that shift?
Reveal the answer and reasoning
Compare compatible defect definitions, exposure denominators, product mix, timing and measurement conditions. A higher count may coexist with a lower rate. Use the stratified evidence to choose a causal test, not a blame statement.
Keep protection active until change is verified
Containment protects against current exposure; correction restores the immediate condition; corrective action addresses a supported cause of recurrence. These decisions can overlap in time but should not be confused. Investigate both occurrence and escape where relevant. A restored machine or a relabelled record does not alone establish that affected output is acceptable or that recurrence is prevented. Verify the appropriate condition and outcomes, keep containment active while evidence is inadequate, and use the designated authority for disposition and exit. Carry effective learning into controls, training and later review. This relationship map complements 8D and NCR routines without claiming that their formal gates are identical.
Follow the method
- Define exposure: Affected work, product and time boundary
- Contain: Protect customers while uncertainty remains
- Restore the condition: Authorized correction of the immediate issue
- Investigate causes: Occurrence and escape mechanisms
- Select corrective action: Address supported recurrence mechanism
- Verify effectiveness: Relevant outcomes and unintended effects
- Authorize closure: Disposition and containment exit by evidence
- Sustain the change: Control, training, ownership and later review
Read the example carefully
Containment does not prove a permanent cause has been removed.
Correction must restore the actual required condition, not merely change a label.
Containment exit and closure require defined authority and effectiveness evidence.
Try it before revealing the answer
An overdue gauge has received a new label, but no authorized calibration or verification record exists. Can the NCR be closed?
Reveal the answer and reasoning
No. Remove the overdue gauge from service as required, complete authorized calibration or verification and restore correct status records. Assess suspect measurement/output exposure and verify the scheduling-system corrective action before closure.
Sources and further reading
- LEI: Problem Solving Resource Guide ↗
Troubleshooting, gap from standard, target condition and open-ended innovation
Method reference; original OPEX scenario and diagram are synthetic teaching content, not source case results. - LEI LeanTech: Prompting for Problem Solving ↗
Analysis method must fit problem; model must not default blindly to 5 Whys
Method reference; original OPEX scenario and diagram are synthetic teaching content, not source case results. - LEI: 5 Whys ↗
Cause chain, not exactly five repetitions; gap-from-standard focus
Method reference; original OPEX scenario and diagram are synthetic teaching content, not source case results. - ASQ: Fishbone diagram ↗
Organize possible causes of a defined effect for investigation; the diagram structures ideas rather than proving them.
Public primary-source summary; underlying paid standards/forms are not reproduced. - PRI: Root cause corrective action ↗
RCCA investigates causes, implements and verifies corrective actions, and supports appropriate Nadcap NCR responses.
This teaching workflow is not the official NCR response form or an accreditation decision. - ASQ: Check sheet ↗
Define the observed event, collection period and recording fields; pilot the form before repeated use.
Public primary-source summary; underlying paid standards/forms are not reproduced. - ASQ: Pareto chart ↗
Rank category totals on one stated measurement basis; cumulative percentages are optional and end at100%.
Public primary-source summary; underlying paid standards/forms are not reproduced. - ASQ: Stratification ↗
Separate observations by relevant source categories so aggregated data do not conceal patterns.
Public primary-source summary; underlying paid standards/forms are not reproduced. - ASQ: Scatter diagram ↗
Plot paired numerical observations to examine association; an apparent relationship alone does not establish causation.
Public primary-source summary; underlying paid standards/forms are not reproduced. - Toyota Virtual Plant Tour: Production System ↗
Andon response, stopping on abnormality, mistake prevention
Method reference; original OPEX scenario and diagram are synthetic teaching content, not source case results. - LEI: Andon ↗
Abnormality signal summons response; fixed-position process stop differs from emergency stop
Method reference; original OPEX scenario and diagram are synthetic teaching content, not source case results. - AIAG/Plexus: APQP and control plan overview ↗
Control plans link process risks and controls, with explicit reaction ownership, containment and return-to-control actions.
Public overview only. Do not reproduce licensed forms or infer a universal sampling frequency or safe-launch exit period.
Take the lesson into your team.
Read the lessons online or use these PDFs to prepare, practise and review with your team. No sign-in needed.
Learner workbook
Printable case worksheets, blank observation records and five calculation exercises; answers are separate.
Download Learner workbook PDF · 169 pages · 10.7 MBAnswer key and coaching notes
Reasoned sample responses, worked calculations and coaching guidance; fictional examples are clearly labelled.
Download Answer key and coaching notes PDF · 105 pages · 8.5 MBMethod and application reference
The native method mechanisms and worked applications for all 68 detailed lessons, in a separate bookmarked portrait reference.
Download Method and application reference PDF · 141 pages · 10.2 MBIllustrated systems atlas
Five illustrated system chapters: 15 Flare concept maps and 26 original workplace teaching cards, with links to all 81 supporting cases and method lessons.
Download Illustrated systems atlas PDF · 69 pages · 55.8 MBPractise the methods in this system.
- Connect protection, problem definition, evidence, causal testing and sustained change.
- Connect useful data collection with hypotheses, alternatives and cause verification.
- Distinguish containment, correction, corrective action and verified closure.
5 Whys with evidence and alternative branches
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Choose a problem-solving approach
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →From broad complaint to a testable problem
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Conflict cloud: challenge assumptions
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Choose the quality tool for the question
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Record defects without changing the denominator
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Rank problems on one declared basis
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →See the distribution without losing the sequence
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Test a relationship without declaring a cause
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Unmix the data before blaming a shift
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Turn fishbone branches into testable hypotheses
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Close an NCR with verified action against recurrence
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Stop the recurring leak
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Make referrals ready
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Send the right shipment
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Make the morning easier
Primary teaching mechanism belongs to problem solving and verified change. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Jidoka and andon: detect, respond, verify restart
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Poka-yoke: prevention versus detection
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Select a chart from the data and sampling plan
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Separate control limits from specifications
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Read spread before the subgroup average
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Monitor one reading at a time
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Chart nonconforming units with the right denominator
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Chart nonconformities per exposure
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Respond to a signal with a defined owner
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Check stability before capability
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Separate part variation from measurement variation
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Check inspection agreement and escape risk
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Link a process risk to an executable control plan
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Make the station check and reaction inseparable
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Build PFMEA from a failure chain to verified action
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Use APQP gates to expose launch risk early
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Distinguish PPAP evidence from production authorization
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Trace one suspect lot through split, merge and rework
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Audit whether critical controls are actually followed
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Control special processes through qualified conditions and records
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Prepare a Nadcap audit with scope-linked evidence
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Locate the applicable automotive requirements
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Distinguish a feedback controller from statistical monitoring
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Connect calibration to a defensible measurement result
Primary teaching mechanism belongs to quality control and dependable evidence. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Gemba: observe work, ask, follow through
Primary teaching mechanism belongs to leadership and daily learning. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Leader standard work supports problem solvers
Primary teaching mechanism belongs to leadership and daily learning. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Daily board: measure, respond, learn
Primary teaching mechanism belongs to leadership and daily learning. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Hoshin: align strategy through catchball
Primary teaching mechanism belongs to leadership and daily learning. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Improvement and coaching kata
Primary teaching mechanism belongs to leadership and daily learning. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Job instruction: steps, key points and reasons
Primary teaching mechanism belongs to leadership and daily learning. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →Make tomorrow ready
Primary teaching mechanism belongs to leadership and daily learning. Supporting links identify application dependencies; they do not make the methods interchangeable.
Explore the connected method →