Manufacturing & Lean Glossary

A workplace organization method that creates clean, orderly environments where abnormalities are immediately visible. The foundation of lean and visual management. Full guide →

A root cause analysis technique where you ask "why?" repeatedly (typically five times) until you reach the fundamental cause of a problem. Simple but powerful when done honestly. Full guide →

A structured problem-solving method used for root cause analysis and corrective action, especially in automotive. Includes team formation, containment, root cause, and verification steps. Full guide →

A structured problem-solving approach from Toyota that fits the entire problem, analysis, and countermeasure on a single A3-size sheet of paper. Forces clarity and conciseness. Full guide →

A change management model: Awareness, Desire, Knowledge, Ability, Reinforcement. Focuses on individual change readiness. Full guide →

A visual signal (typically a light or board) that alerts the team to an abnormal condition on the production line. Operators pull a cord or press a button to activate it, triggering immediate response.

The first pillar of TPM. Operators take ownership of basic equipment care: cleaning, inspecting, lubricating, and detecting abnormalities. Frees maintenance for higher-value work.

The percentage of planned production time that the machine is actually running. One of three OEE factors. Availability = Run Time ÷ Planned Production Time.

The number of units produced between changeovers. Smaller batches mean shorter lead times and less WIP but more changeovers. Batch size calculator →

The process step with the lowest throughput capacity. The bottleneck determines the maximum output of the entire system. See Theory of Constraints.

Actual output divided by maximum possible output, expressed as a percentage. High utilization (90%+) sounds good but leads to exponentially growing queue times. Calculator →

The time to switch production from one product to another. Includes cleanup, tooling change, adjustment, and first-article validation. Reduced through SMED.

The ongoing effort to improve products, services, or processes incrementally. Core to lean and Six Sigma. Full guide →

The time to complete one unit of work from start to finish. Different from takt time (demand-based) and lead time (total elapsed). Calculator →

Define, Measure, Analyze, Improve, Control — the core problem-solving cycle in Six Sigma. Used for data-driven improvement of existing processes.

A metric that normalizes defect rates across processes with different complexity levels. Used to calculate sigma level. Calculator →

Any period when equipment is not producing during planned production time. Includes planned (changeover, PM) and unplanned (breakdowns, material shortage). Cost calculator →

A production scheduling goal where every product variant is produced at least once per day. Requires very short changeovers (achieved through SMED).

The percentage of units that pass through a process correctly the first time, without rework or repair. A truer quality metric than final yield. Calculator →

A cause-and-effect diagram shaped like a fish skeleton. Organizes potential causes of a problem into categories (Man, Machine, Method, Material, Measurement, Environment). Full guide →

The movement of materials and information through a value stream with minimal stops, batches, or waiting. Ideal flow is single-piece, continuous, and pull-based.

The actual place where work is done — the shop floor, the warehouse, the assembly line. Leaders go to the gemba to observe reality firsthand. Full guide →

“Go and see for yourself.” A Toyota principle that decisions should be based on firsthand observation at the gemba, not reports or assumptions.

Leveling production volume and mix over time to reduce unevenness (mura). Instead of producing 1,000 of Product A then 500 of Product B, produce a mixed sequence throughout the day.

A strategic planning process that aligns organizational goals from top to bottom. Each level translates the strategy into specific, measurable actions — creating a "golden thread" from boardroom to shop floor.

“Automation with a human touch.” Machines detect abnormal conditions and stop automatically. Prevents defects from being passed downstream. One of the two pillars of TPS (with JIT).

Producing and delivering exactly what is needed, when it is needed, in the amount needed. One of the two pillars of TPS. Requires pull systems, level production, and reliable processes.

Japanese for “change for better.” Continuous, incremental improvement involving everyone. Can be daily small improvements or structured multi-day kaizen events. Full guide →

A visual signaling system that triggers production or material replenishment based on actual consumption rather than forecasts. Cards, bins, or empty spaces act as signals. See push vs. pull.

A measurable value that demonstrates how effectively an operation is achieving key objectives. Common manufacturing KPIs: OEE, schedule adherence, FPY, TRIR, cost per unit.

The total elapsed time from order to delivery (or from raw material to finished product). Includes processing time, queue time, move time, and wait time. Reducing lead time is a primary lean goal.

A systematic approach to identifying and eliminating waste through continuous improvement while maximizing value to the customer. Originated from the Toyota Production System. Full guide →

The ratio of value-added work time to total available time across all stations on a production line. Measures how well the line is balanced. Calculator →

WIP = Throughput × Lead Time. A fundamental relationship that explains why reducing WIP shortens lead time. Calculator →

The average time between equipment breakdowns. A key maintenance reliability metric. Higher is better. Improved through TPM and preventive maintenance.

The average time to restore equipment after a failure. Lower is better. Improved through spare parts availability, technician training, and standardized repair procedures.

Any activity that consumes resources but does not add value for the customer. The 8 wastes: Defects, Overproduction, Waiting, Non-utilized talent, Transportation, Inventory, Motion, Extra processing.

Variation and irregularity in workload or process. Causes overburden (muri) and waste (muda). Addressed through heijunka (production leveling).

Unreasonable stress on people or equipment caused by uneven demand or poor process design. Leads to breakdowns, injuries, and defects.

Availability × Performance × Quality. The gold standard metric for equipment productivity. World class is 85%+. Full guide → | Calculator →

The structured cadence of meetings, reviews, and walks that keeps an operation aligned: shift handoffs, daily stand-ups, weekly reviews, monthly business reviews. Full guide →

A technique that identifies the vital few causes that account for the majority of a problem. Typically, 20% of causes create 80% of issues. Focus on the tallest bars first.

The Deming cycle. A four-step improvement loop: Plan the change, Do it on a small scale, Check the results, Act to standardize or adjust. Full guide →

Any device or process design that prevents errors from becoming defects. Examples: asymmetric connectors, sensors, interlocks. Full guide →

Production is triggered by actual consumption downstream, not by forecasts. Work is "pulled" through the system by customer demand. Opposite of push. Full guide →

The process of finding the fundamental cause of a problem and implementing a permanent fix. Includes methods like 5 Whys, Fishbone, 8D, and Fault Tree Analysis. Full guide →

Extra inventory held as a buffer against demand variability and supply uncertainty. Calculated based on service level, demand variation, and lead time variation. Calculator →

The percentage of planned production that was actually completed on time and in full. A key delivery metric for shift and daily performance.

A statistical measure of process capability. Higher sigma = fewer defects. 3 sigma = 66,800 DPMO. 6 sigma = 3.4 DPMO. Calculator →

A systematic method for reducing changeover time. Separates internal setup (machine stopped) from external setup (done while running), then converts internal to external. Calculator →

Using control charts to monitor process performance over time. Distinguishes between normal variation (common cause) and abnormal variation (special cause) that requires action.

The current best-known method for performing a task, tied to takt time. Defines sequence, timing, and WIP. The baseline from which all improvement starts. Full guide →

Available production time ÷ customer demand. The pace at which you need to produce to meet demand. Not the same as cycle time. Calculator →

The rate at which a system produces finished output. Constrained by the bottleneck. Calculator →

A layered daily management system. T1 = team-level (5 min), T2 = department (10 min), T3 = plant (15 min), T4 = executive. Problems escalate up; actions cascade down. Full guide →

A system for maintaining equipment through operator involvement (autonomous maintenance) and proactive planning. Goal: zero breakdowns. Full guide →

Number of OSHA-recordable injuries per 200,000 hours worked. The standard safety metric for comparing incident rates across facilities and industries.

All activities (value-adding and non-value-adding) required to bring a product from raw material to the customer. Mapped to identify waste and improvement opportunities. Full guide →

Making the status of work, performance, and standards visible so anyone can understand the situation in 5 seconds without asking questions. Full guide →

Inventory that has started production but is not yet finished. Related to lead time through Little's Law: WIP = Throughput × Lead Time. Lower WIP = shorter lead times.

“Across everywhere.” The practice of sharing best practices and improvements horizontally across teams, lines, or plants. A solution found in one area is actively spread to all similar areas.