Clear, practical definitions of the key terms used in quality management, EHS and continuous improvement in manufacturing. A working vocabulary for operations, quality and EHS teams.
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Terms covering quality management fundamentals: how non-conformities are captured, how their root causes are identified, and how corrective and preventive actions are structured.
Any deviation from a specification, standard or expected outcome: a defect, an out-of-tolerance reading, a failed inspection. The starting point of most quality improvement processes. Covers the related term “deviation”.
A structured process for identifying the root cause of a non-conformity, implementing a corrective action, and taking preventive steps to stop recurrence. Required by ISO 9001 clause 10.2.
A side-by-side definition of the two halves of CAPA: corrective action eliminates the cause of an existing non-conformity, preventive action eliminates the cause of a potential one before it occurs.
A team-based problem-solving methodology developed at Ford, structured in eight sequential steps from problem definition (D1) to team recognition (D8). A rigorous way to execute a CAPA.
A root cause analysis technique that asks “why?” repeatedly, typically five times, until the underlying cause is reached. Often used as the root cause step inside an 8D or CAPA workflow.
The umbrella practice of identifying the underlying cause of a problem rather than treating its symptoms. Includes 5-Why, fishbone diagrams, fault tree analysis and the 8D methodology.
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Terms describing how improvement actions are tied to outcomes: closed-loop systems, KPI verification, recurrence detection, the broader CI methodologies and the cost of getting it wrong.
A structured approach in which every corrective action is monitored for recurrence, and the loop only closes once the same problem stops coming back and the relevant KPI confirms the improvement.
Plan, Do, Check, Act: the four-step iterative management framework for continuous improvement. The Check and Act stages are the most commonly skipped in practice.
The practice of measuring whether a corrective action produced a measurable change in the KPI it was intended to influence, observed over time and across multiple closed loops.
The general principle that an improvement action is not complete until its effect has been verified, by direct observation, audit results or recurrence checks. Broader than KPI impact verification.
The practice of identifying when the same defect, incident or non-conformity comes back after a corrective action has been closed. The primary signal that a previous fix did not address the root cause.
The total cost incurred as a result of defects, failures and non-conformities. Includes internal failure costs (scrap, rework, downtime) and external failure costs (returns, warranty, recalls).
The proportion of input materials or production runs that fail to meet quality standards and result in scrap, rework or downgrading. A primary indicator of process stability.
A long-term management discipline that systematically improves cost, quality, delivery and safety through methods such as Lean, Six Sigma and TPM, combined with a culture of continuous improvement.
A QMS documents the quality system to satisfy standards (ISO 9001, ISO 13485, FDA). Continuous improvement software runs the improvement loop on top of those records.
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Terms covering environmental, health and safety management on the shop floor: leading-indicator reporting, on-site observation practices, and quantitative risk assessment.
An unplanned event that did not result in injury or damage but had realistic potential to do so. A leading indicator: capturing them systematically is the foundation of proactive safety management.
A management practice in which leaders visit the shop floor (gemba, the actual place where work happens) to observe operations directly, identify problems at the source and engage with operators.
A quantitative risk assessment method that scores hazards by multiplying probability, exposure and consequence to produce a single risk rating. Used to prioritise corrective actions by objective risk level.