Lean Dictionary

5 Whys is a root cause analysis technique that asks 'why' repeatedly to trace symptoms back to fundamental causes.

5S is a workplace organization methodology using five Japanese principles: Sort, Set in Order, Shine, Standardize, and Sustain.

A3 Problem Solving is a structured approach that documents the problem-solving process on a single 11x17 inch (A3) page.

Andon is a visual signaling system that alerts teams to problems, status changes, or requests for assistance in real time.

Availability is the percentage of scheduled time that equipment is actually available for production, accounting for downtime from breakdowns and changeovers.

Bottleneck analysis identifies the constraint limiting system throughput, focusing improvement where it matters most.

Buffer stock is inventory held to protect against variability in production or demand, distinct from safety stock for supply variation.

Catchball is the back-and-forth dialogue process for aligning goals and plans between organizational levels in hoshin kanri.

Cellular manufacturing organizes equipment and people into cells that produce complete products or components with minimal handling.

A Champion is a senior leader who sponsors Six Sigma projects, removes organizational barriers, and ensures resources and support for project success.

Change management is a structured approach to transitioning individuals, teams, and organizations from current state to desired future state.

Changeover is the process of converting equipment from producing one product to another, including setup, adjustment, and trial runs.

The Coaching Kata is a structured pattern of questions that develops scientific thinking in others through guided practice.

Condition monitoring tracks equipment health indicators in real-time to detect degradation and predict failures before they occur.

Continuous improvement is the ongoing effort to enhance products, services, or processes through incremental and breakthrough improvements.

A control chart is a statistical tool that monitors process variation over time, distinguishing between common cause and special cause variation.

Corrective action is a systematic process for eliminating the root cause of an identified problem to prevent recurrence.

Cpk is a process capability index that measures how well a process performs relative to specification limits, accounting for both variation and centering.

Customer focus is the practice of understanding and prioritizing customer needs as the basis for all operational decisions.

Cycle time is the elapsed time to complete one unit of work from start to finish of a specific process step.

DFSS (Design for Six Sigma) is a methodology for designing new products or processes to achieve Six Sigma quality levels from the start.

DMADV is the five-phase Design for Six Sigma methodology: Define, Measure, Analyze, Design, and Verify for creating new products or processes.

DMAIC is the five-phase problem-solving methodology used in Six Sigma: Define, Measure, Analyze, Improve, and Control.

DPMO (Defects Per Million Opportunities) is a Six Sigma metric that measures process quality by calculating defects relative to total opportunities.

Drum-Buffer-Rope is a TOC scheduling method that synchronizes production to the constraint, protects it with buffers, and controls material release.

Early equipment management applies TPM lessons learned to new equipment design and installation, building maintainability in from the start.

Elevate is the fourth of TOC's Five Focusing Steps—investing to increase constraint capacity after exploitation is maximized.

EPEI measures how frequently a process can produce every product in its mix, indicating production flexibility and responsiveness.

FIFO (First In, First Out) ensures items are processed or consumed in the order they arrived, preventing aging and maintaining flow.

First Pass Yield (FPY) is the percentage of units that complete a process step correctly the first time without rework, repair, or rejection.

A fishbone diagram organizes potential causes of a problem into categories, visually structured like fish bones around a spine.

Gage R&R (Repeatability and Reproducibility) is a study that quantifies measurement system variation to ensure data quality for process improvement.

Gemba means 'the real place' - the location where work happens and value is created, where leaders must go to understand actual conditions.

A gemba walk is a structured observation of the workplace where leaders go to see, ask questions, and understand actual conditions.

A Green Belt is a part-time Six Sigma practitioner who leads smaller improvement projects while maintaining regular job responsibilities.

Greenfield refers to designing new operations from scratch with lean principles built in from the start, without legacy constraints.

Heijunka is production leveling - smoothing the volume and mix of production to reduce variability and enable consistent flow.

A heijunka box is a visual scheduling tool that levels production by distributing work evenly across time periods.

The hidden factory is the informal collection of rework, repair, and correction activities that consume resources but don't appear in official metrics.

A histogram is a bar chart showing the frequency distribution of continuous data, revealing patterns in process variation and shape.

Hoshin Kanri is a strategic planning methodology that aligns organizational goals with daily actions through collaborative goal deployment.

An hourly production board tracks output versus target each hour, making performance and problems visible in real time.

The Improvement Kata is a four-step practice routine for developing scientific thinking and systematic problem-solving skills.

Inventory turns measure how many times inventory is sold and replaced in a period, indicating the velocity of material flow.

An Ishikawa diagram is a cause-and-effect diagram developed by Kaoru Ishikawa for systematic root cause analysis.

Jidoka is automation with a human touch - building quality into the process by stopping immediately when a defect is detected.

Job Instruction is a structured method for training workers quickly and correctly using job breakdown sheets and a four-step teaching process.

Just-in-Time (JIT) is a production strategy that produces only what is needed, when it is needed, in the amount needed.

Kaikaku is radical, breakthrough improvement that fundamentally transforms a process, contrasted with incremental kaizen improvements.

Kaizen is the philosophy of continuous, incremental improvement involving everyone in an organization to eliminate waste and improve processes.

A kaizen blitz is an intensive, rapid improvement event focused on making immediate changes to a specific process.

A kaizen event is a focused, time-boxed improvement activity where a team intensively improves a specific process.

Kamishibai boards are visual audit systems using cards to ensure regular checks of process conditions and standards.

Kanban is a visual signal system that triggers production or movement of materials based on actual consumption.

The Kano Model categorizes customer requirements into must-haves, performance factors, and delighters to guide product and service design priorities.

Kata is a structured routine or pattern that, through practice, builds capability and becomes second nature.

A KPI (Key Performance Indicator) is a measurable value that demonstrates how effectively an organization achieves key business objectives.

Leader standard work is a defined routine of activities that ensures leaders regularly perform essential management tasks like gemba walks and coaching.

Lean is a methodology for continuous improvement that maximizes customer value while eliminating waste, originating from the Toyota Production System.

A lean promotion office is an internal group responsible for coordinating, supporting, and sustaining lean transformation efforts across an organization.

Leveling is the practice of smoothing workload over time to eliminate peaks and valleys that cause waste and overburden.

Line balancing distributes work elements across workstations to achieve even cycle times close to takt time.

A Master Black Belt is an expert Six Sigma practitioner who trains and mentors Black Belts, develops methodology, and guides organizational deployment.

A milk run is a fixed-route delivery system that picks up and delivers materials on a regular schedule, like traditional milk delivery.

Minor stops are brief equipment interruptions lasting under 5 minutes that individually seem insignificant but collectively cause major productivity loss.

Mistake-proofing is designing processes and devices to prevent human errors or make them immediately detectable.

MTBF (Mean Time Between Failures) measures average equipment reliability by calculating the average operating time between breakdowns.

MTTR (Mean Time To Repair) measures average maintenance responsiveness by calculating the average time to restore failed equipment to operation.

Muda refers to waste in any process - activities that consume resources without creating value for the customer.

Mura refers to unevenness or inconsistency in processes that causes waste and makes work unpredictable.

Muri refers to overburden or unreasonable stress placed on people or equipment beyond their capacity.

Nemawashi is the Japanese practice of building consensus through informal discussions before formal decisions are made.

Obeya is a 'big room' where cross-functional teams co-locate to manage projects with visual displays of status and plans.

OEE (Overall Equipment Effectiveness) measures manufacturing productivity by combining availability, performance, and quality into a single percentage.

One-piece flow is the ideal state where items move through processes one at a time without batching, waiting, or accumulation.

Operational excellence is a philosophy of continuous improvement that engages everyone in systematic, sustainable enhancement of business performance.

Out-of-cycle work is any task an operator must perform that doesn't occur every cycle, disrupting standard work rhythm and timing.

Paced withdrawal is the scheduled removal of finished goods at fixed intervals to create consistent demand signals upstream.

Pack-out quantity is the standard number of units packaged together for shipping or movement between processes.

A Pareto chart combines bar and line graphs to show which factors contribute most to a problem, guiding improvement priorities.

PDCA (Plan-Do-Check-Act) is a four-step continuous improvement cycle for testing changes and learning from results.

Perfection in lean thinking is the theoretical state of zero waste, instant response, and perfect quality—the guiding star for continuous improvement.

PFEP is a database documenting material flow specifications for every part number: storage locations, quantities, delivery methods, and container types.

Pitch is the time increment for releasing work and moving materials, calculated as takt time multiplied by pack-out quantity.

Poka-yoke is mistake-proofing - designing processes and devices to prevent errors or make them immediately obvious.

A Process Capacity Sheet (PCS) calculates the capacity of each machine in a sequence to identify bottlenecks and support line balancing.

A product family is a group of products that share similar processing steps and equipment, enabling flow cell design and value stream focus.

A product family matrix is a tool that maps products against processing steps to identify product families with similar routings.

A production analysis board displays real-time production status, targets, and problems to enable rapid response and continuous improvement.

Psychological safety is a shared belief that the team is safe for interpersonal risk-taking—speaking up, asking questions, and admitting mistakes.

A pull system produces only when downstream processes signal demand, preventing overproduction and enabling flow.

A push system produces based on forecasts and schedules, pushing work downstream regardless of actual demand.

A quality circle is a small group of employees who meet regularly to identify, analyze, and solve work-related quality and productivity problems.

Quick changeover is the practice of reducing the time required to switch equipment or processes from one product to another.

Red tagging is a visual technique for identifying items that may be unnecessary, marking them for evaluation and potential removal.

Respect for People is a foundational lean principle that values human potential, dignity, and development alongside process improvement.

Ringi is the Japanese consensus-based decision-making process where proposals circulate for approval through multiple levels.

Root cause analysis is a systematic process for identifying the fundamental reasons why problems occur, enabling permanent corrective action.

A run chart plots data points in time sequence to reveal trends, shifts, cycles, or patterns that indicate process changes.

Safety stock is inventory held to protect against uncertainty in supply—delivery delays, quality rejections, or supplier disruptions.

Seiketsu is the fourth of the 5S steps - creating standards and systems to maintain Sort, Set in Order, and Shine.

Seiri is the first of the 5S steps - sorting through items to remove what is unnecessary from the workplace.

Seiso is the third of the 5S steps - cleaning the workplace thoroughly while inspecting for abnormalities.

Seiton is the second of the 5S steps - organizing remaining items so everything has a designated, labeled place.

Servant leadership is a philosophy where leaders prioritize serving their teams—enabling success by removing obstacles and providing support.

Setup reduction focuses on minimizing the time and effort required to change from one product, batch, or configuration to another.

A shadow board organizes tools with painted outlines showing each tool's designated location, making missing items immediately obvious.

Shitsuke is the fifth of the 5S steps - maintaining discipline through training, audits, and continuous practice.

The six big losses are the primary categories of equipment productivity loss that TPM targets: breakdowns, setup, idling, speed loss, defects, and startup.

Six Sigma is a data-driven methodology for eliminating defects and reducing variation in processes to achieve near-perfect quality.

SMED (Single-Minute Exchange of Die) is a systematic approach to reducing changeover time to under ten minutes.

A spaghetti diagram traces the path of movement through a workspace, revealing inefficient layouts and excessive travel.

Speed loss is the gap between actual equipment running speed and its designed maximum rate, reducing output without causing stops.

Standard work documents the best-known sequence, timing, and layout for performing work consistently and safely.

Standardization is establishing and following the current best-known method for performing work consistently and predictably.

A Standardized Work Chart (SWC) is a top-down diagram of a work area showing the operator walking path, work sequence, quality checks, and safety points for a standardized cycle.

A Standardized Work Combination Table (SWCT) plots manual, automatic, walking, and waiting time for each work element against takt time to balance a work cycle.

Subordinate is the third of TOC's Five Focusing Steps—aligning all non-constraint resources to support and never impede constraint performance.

A supermarket is a controlled inventory location where products are stored for downstream pull, similar to retail supermarket shelves.

Takt image is a visual representation of what should happen at each takt time interval, making abnormalities immediately visible.

Takt time is the pace of production needed to match customer demand - the heartbeat that synchronizes all work.

A team leader is a front-line lead who supports a small group of operators, responding to problems and maintaining standard work.

Throughput Accounting is a TOC decision-making method that evaluates choices based on their impact on Throughput, Inventory, and Operating Expense.

A Time Observation Sheet (TOS) records repeated cycle times for each work element to establish the lowest repeatable time used in standardized work.

Time study is the systematic measurement and analysis of work element times to establish standards and identify improvement opportunities.

Total Productive Maintenance (TPM) is a holistic approach to equipment maintenance that maximizes equipment effectiveness through operator involvement and proactive care.

The Toyota Production System (TPS) is Toyota's integrated manufacturing approach combining just-in-time, jidoka, and respect for people.

Trade-off curves document the relationships between design parameters, showing how improving one attribute affects others.

Training Within Industry (TWI) is a structured methodology for developing supervisory skills in job instruction, job methods, and job relations.

True North is the ideal state or perfect vision that guides continuous improvement direction, even if never fully achieved.

A value stream is the complete sequence of activities required to transform raw materials or information into a product or service delivered to the customer.

Value Stream Mapping (VSM) is a visual tool for analyzing material and information flow from customer order to delivery.

Value-stream improvement focuses on optimizing the entire flow from raw material to customer, not just individual process steps.

Visual management uses visual signals and displays to make process status, performance, and abnormalities immediately obvious.

Voice of Customer (VOC) is the structured process of capturing customer needs, expectations, and preferences to guide product and process design.

Waste is any activity that consumes resources without creating value for the customer - the target of lean improvement.

Work instructions are detailed step-by-step directions for performing specific tasks correctly and consistently.

A Yellow Belt has foundational Six Sigma knowledge to participate on project teams and apply basic improvement concepts in daily work.