All problems by area
Production
- High scrap and rework: Scrap or rework is above target, often spread over several defect types.
- Process drifts or is unstable: Measurements jump or drift between shifts, batches or after set-ups.
- Cpk below requirement: The customer asks for Cpk ≥ 1.33 or 1.67 and the study shows less.
- Machine downtime and low OEE: Planned output is not reached; machines stop often or run slowly.
- Long changeovers: Set-ups take long, so batches get bigger and inventory grows.
- Repeated operator errors: Wrong part, missing part, wrong orientation or skipped step keeps coming back.
Quality
- Customer complaint: The customer reports defective parts and expects containment and an 8D.
- Defects escape inspection: Defects are made and also not detected; the customer finds them first.
- The same defect keeps coming back: Actions were taken, but the defect returns after weeks or months.
- Measurement disputes: You and the customer or supplier measure different values on the same part.
Suppliers
- Unreliable supplier quality: Repeated defective deliveries, sorting at incoming inspection and line stops.
- Selecting a new supplier: Sourcing needs a decision and quality must say whether the supplier is capable.
- Late supplier deliveries: Parts arrive late or incomplete and production plans change at short notice.
- Too much incoming inspection: Incoming inspection checks a lot but defects still reach the line.
Launch and engineering
- Problems after SOP: Scrap, delays and complaints in the first months after start of production.
- Design hard to produce: Tolerances or features cannot be made capably in production.
- No standards, everybody works differently: Different shifts or operators do the same job in different ways.
Maintenance
- Frequent breakdowns: Unplanned stops, emergency repairs and the same failures again.
- Spare parts missing: Repairs wait for parts, or the store is full of parts nobody uses.
Logistics
- High inventory and long lead time: Full warehouses, long lead times and yet missing parts.
- Damage in handling and transport: Scratches, dents and mixed parts from packaging and transport.
- Missing or wrong parts at the line: Line stops because a part is missing, or a wrong variant is delivered.
Customer
- Warranty and field failures: Parts fail at the end customer after months or kilometres.
- Late deliveries to the customer: Customer orders ship late; premium freight and escalations.
- Low customer satisfaction: Poor customer scorecard, lost business or escalation status.
Management system
- Audit nonconformities: Major or minor findings from certification, customer or internal audits.
- Poor KPI tracking and follow-up: KPIs are reported but nobody acts on them, or the numbers are not trusted.
- Departments pull in different directions: Production, quality and logistics have conflicting targets.
People and safety
- Skill gaps and new operators: New or rotating people make more defects; knowledge sits with a few experts.
- Unsafe acts and near misses: Near misses, minor injuries and unsafe shortcuts on the shop floor.
Five rules for choosing a method
- Contain first, analyse second. Protect the customer before you look for the root cause.
- Trust the data only after the measurement check. Gage R&R or attribute agreement before charts and experiments.
- Match the effort to the problem. A 5 Why on the shop floor, an A3 for a team problem, DMAIC for chronic losses.
- Prove the root cause. Switch it on and off, or confirm it with a test, before you invest in actions.
- Lock the result. Update the PFMEA, control plan, work instruction and audit checklist, or the problem comes back.
Frequently asked questions
Which problem-solving tool should I use?
Start from the problem, not the tool. Customer complaints need an 8D, internal improvements fit an A3, chronic problems with many causes need data (Pareto, multi-vari, DOE), and repeated human errors need error-proofing. The selector gives the methods to start with for each typical problem.
What is the difference between 8D, A3 and DMAIC?
8D is the customer complaint format with containment and verified root cause. A3 is a one-page PDCA story for internal problems. DMAIC is a Six Sigma project for chronic problems where the cause is hidden in data and takes weeks to months. All three follow the PDCA logic.
Should I always use a fishbone diagram and 5 Why?
They are good for structuring ideas, but they only list and explain candidate causes. Verify the cause with data or by switching it on and off. For problems driven by several interacting factors, use multi-vari studies and designed experiments.
Why check the measurement system first?
If the gauge or the visual inspection cannot see the problem reliably, every chart, Cpk and experiment is built on noise. A Gage R&R or attribute agreement study takes a day and can save weeks of wrong analysis.