Lean Terminology

Lean Sigma Dictionary

3P—Production Preparation Process; sometimes known as Product, Process and People. A methodology used to approach new product design (and the associated manufacturing of that product). Involves evaluating multiple different ideas, and mocking up production lines or products using cardboard, wood, tape, etc., in order to more effectively evaluate options, which incorporates the use of many lean tools and principles.

5 Whys—The practice of asking why repeatedly when a problem is encountered in order to get beyond the obvious symptoms and to discover the root cause.

6S—Six related terms (Safety, Sort, Set in Order, Shine, Standardize, Sustain), beginning with the letter S, describing practices conducive to visual management and workplace organization.

8D—The Eight Disciplines of Problem Solving (8D) is a popular method for solving complex problems. Focused on product and process improvement, its purpose is to identify, correct, and eliminate recurring problems.  It establishes a permanent corrective action based on statistical analysis of the problem and on the origin of the problem by determining the root causes.

A3—A problem-solving tool that incorporates the problem statement, goal, background, analysis, corrective actions and action plan on a single sheet of large (A3 size, approximately 11”x17”) paper.  It often includes graphics, charts and graphs.

Andon—A visual management tool that highlights the status of the operations in an area at a single glance and that signals whenever an abnormality occurs.

Autonomous Maintenance (AM)—Autonomous maintenance is “independent” maintenance carried out by the operators of the machines rather than by dedicated maintenance technicians.  Unlike traditional maintenance programs where the operators run the machines until they break or become due for maintenance and then hand them to the maintenance department, autonomous maintenance has the operators performing the simpler (and safe) maintenance routines such as lubrication, bolt tightening, cleaning and also inspection and monitoring.

Cpk—A short-term process index that measures how close a process is running to its specification limits, relative to the natural variability of the process.

Cycle Time—How often a part or product is completed by a process.  Also, the time it takes an operator to go through all work elements before repeating them.

Days of Inventory— The number of days of inventory that a facility currently has. It is calculated by dividing the total inventory dollars (including WIP, raw and finished goods) by the average daily usage dollars.  This metric is closely related to Inventory Turns.

Design for Six Sigma (DFSS)—DFSS is used to design, or re-design, a product or service from the ground up.  DFSS seeks to avoid manufacturing/service process problems by using advanced techniques to avoid process problems at the outset.  Customer expectations be completely understood before a design can be completed and implemented.

DMADV—Define, Measure, Analyze, Design and Verify, a Design for Six Sigma (DFSS) methodology.

  • Define the project goals and customer requirements
  • Measure and determine customer needs and specifications
  • Analyze the process options to meet the customer needs
  • Design (detailed) the process to meet the customer needs
  • Verify the design performance and ability to meet customer needs

DMAIC—An acronym for Define, Measure, Analyze, Improve and Control, DMAIC refers to a data-driven improvement cycle used for improving, optimizing and stabilizing business processes and designs.

  • Define the problem/opportunity, the project goals and customer (internal and external) requirements
  • Measure process performance
  • Analyze the process to determine root causes of variation and defects
  • Improve process performance by addressing and eliminating the root causes
  • Control the improved process and future process performance

Error-Proofing—Methods that help associates avoid mistakes in their work.  Also called mistake-proofing, poka-yoke.

First-In, First-Out (FIFO)—The principle and practice of maintaining precise production and conveyance sequence by ensuring that the first part to enter a process or storage location is also the first part to exit.

Flow—Producing and moving one item at a time (or a small and consistent batch of items) through a series of processing steps without interruption, with each step making just what is requested by the next step.  Also called continuous flow, one-piece flow, single-piece flow, and make one, move one.

Gemba—The Japanese term for “actual place”, used to describe the place where value-creating work occurs.  Real improvement requires a deep understanding of the process that can only be gained by direct observation at the gemba.

Gemba Walk—A visit to the work area to see the current condition, witness the value creation process and look for waste.

Hoshin Kanri—A management process that aligns an organization’s functions and activities with its strategic objectives.  This process ensures that both daily process improvement activities, and efforts that support future-reaching breakthrough objectives, are working synergistically to move the organization steadily forward.

Inventory Location Diagram—An inventory location diagram gives a visual indication of where (relative to the floor plan) the inventory resides within the value stream.  When combined with a value stream map (VSM), it shows where the flow is constricted.

Inventory Turns—A measure of how quickly materials are moving through a facility or through an entire value stream.  Most common calculation: Inventory turns = annual cost of goods sold / average value of inventories during the year.

Jidoka—Providing machines and operators the ability to detect when an abnormal condition has occurred and immediately stop work.

Just-in-Time (JIT)—Just-in-time production is a system that makes and delivers what is needed, when it is needed, and in the amount needed.  It aims for the total elimination of all waste to achieve the best possible quality, lowest possible cost and use of resources, and the shortest possible production and delivery lead times.

Kaizen—Continuous improvement of an entire value stream or an individual process to create more value with less waste.  A kaizen blitz is an improvement effort that yields results within 3 to 5 days.

Kanban—A signaling device that gives authorization and instructions for the production or withdrawal of items in a pull system.  Kanban cards are the most common example of a signaling device.  Colored balls, electronic signals, or any other device that can convey the needed information while preventing incorrect instructions are considered to be kanban.

Key Process Indicators (KPIs)— KPIs are measurable values that help understand how effectively key business objectives are being achieved.

Last-In, First-Out (LIFO)—The principle and practice of depleting inventory in a last-in, first-out manner, meaning that the most recently produced items are recorded as sold first.

Leader Standard Work (LSW)— LSW involves walking the gemba (the place where value is added), observing abnormalities, asking questions, and supporting people in the improvement processes.

Lead Time—The time required for a product to move all the way through a process, or a value stream, from start to finish.

Level Loading (Heijunka)—Leveling the type and quantity of production over a fixed period of time.  This enables production to efficiently meet customer demands while avoiding batching, thus lowering overall costs in the value stream.

Muda (Waste)—Any activity that consumes resources without creating value for the customer. There are 8 generally accepted forms of waste:

  • Defects
  • Overproduction
  • Waiting
  • Not Utilizing Employees’ Knowledge, Skills and Abilities
  • Transportation
  • Inventory
  • Motion
  • Excess Processing

Mura—Unevenness in an operation; a fluctuating schedule not caused by end consumer demand, but by the production system, or an uneven work pace in an operation causing associates to hurry and then wait.

Muri—Overburdening equipment or associates by requiring them to run at a higher, or more difficult, pace with more force and effort for a longer period of time than equipment designs and appropriate workforce management allow.

Non-value-Added Time—The time spent on activities that add costs, but no value, to an item from the customer’s perspective.

Overall Equipment Effectiveness (OEE)—A measure of how effectively equipment is being used. Calculated by multiplying three elements—availability, performance, and quality—together.

Plan, Do, Check, Act (PDCA)— An improvement cycle based on the scientific method of proposing a change in a process, implementing the change, measuring the results, and taking appropriate action. It has four stages:

  • Plan: Determine goals for a process and needed changes to achieve them
  • Do: Implement the changes
  • Check: Evaluate the results in terms of performance
  • Act: Standardize and stabilize the change or begin the cycle again, depending on the results

Plan for Every Part (PFEP)—A detailed plan for each part used in a production process, showing everything relevant to managing the process with no errors or waste.

Point-of-Use Storage—Storing production parts and materials as close as possible to the operations that require them.

Poka-Yoke—see “Error-Proofing”

Ppk— (Process Performance Index): A long-term process index that measures how close a process is running to its specification limits, relative to the natural variability of the process.

Predictive Maintenance (PdM)—Predictive Maintenance techniques are designed to help determine the condition of in-service equipment in order to predict when maintenance should be performed.  The main promise of Predictive Maintenance is to allow convenient scheduling of corrective maintenance, and to prevent unexpected equipment failures.

Preventive Maintenance (PM)—An equipment servicing approach considered a precursor to Total Productive Maintenance based on regularly scheduled checking and overhauling by maintenance personnel to decrease breakdowns and increase equipment life.

Process Map—A simple diagram of the major steps in a process, without a value-added/non-value-added ratio.  Often used to help highlight specific wastes.

Pull Production—A method of production control in which downstream activities signal their needs to upstream activities.  Pull production strives to eliminate overproduction.

Push Production—A production environment in which processes make whatever they can make, without regard for whether the next process is ready to, or capable of, accepting that work.  Often results in overproduction and other forms of waste.

Quality at the Source—The principle that quality output is not only measured at the end of the production line, but at every step of the production process.  Quality is the responsibility of each individual who contributes to the production, or on-time delivery, of a product or service.

Spaghetti Diagram—A spaghetti diagram is a method that uses a continuous line to trace the path and distance traveled of a particular object, material, or person throughout a process.  It is often illustrated on a floor map diagram that contains the entire process being evaluated.  The purpose of this tool is to help expose inefficient process layouts, unnecessary travel distance between process steps, and overall process waste.

Standard Deviation—a measure of how spread out numbers are.  The symbol for standard deviation is the Greek letter sigma (σ), and the formula is the square root of the variance. (Variance is the average of the squared differences from the mean.)

Standard Work—Establishing precise procedures for each associate’s work in a process.  Includes takt time, work sequence, and quality and inventory requirements.

Statistical Process Control (SPC)—Statistical process control (SPC) is a method for monitoring, controlling and, ideally, improving a process through statistical analysis.  Monitoring and controlling the process ensures that it operates at its full potential. At its full potential, the process can make as much conforming product as possible with a minimum (if not an elimination) of waste (rework or scrap).

Single Minute Exchange of Die (SMED)—A process for changing over production equipment from one part to another in as little time as possible.  SMED refers to the target of reducing changeover times to a single digit, or less than 10 minutes.  Also referred to as quick changeover.

Six Sigma—A quality standard of 3.4 defects per one million opportunities.  A methodology that uses the DMAIC (Define, Measure, Analyze, Improve, Control) approach to improve a process.

Takt Time—The rate at which your customer (internal or external) “demands” your product.  Calculated by available production time divided by customer demand.  Takt is German for a precise interval of time, such as the pace of a metronome.

Time Value Map—A time value map is a graphical description of value-added and non-value-added time in a process.

True North Metrics (TNM)—Metrics that align with an organization’s strategic and philosophical vision or purpose.

Total Productive Maintenance (TPM)—A set of techniques to help ensure that every machine in a production process is always able to effectively perform its required tasks.

Total Quality Management (TQM)—A management philosophy in which all departments and associates are responsible for continuously improving quality ensuring products and services meet, or exceed, customer expectations.

Takt Time—The rate at which your customer (internal or external) “demands” your product.  Calculated by available production time divided by customer demand.  Takt is German for a precise interval of time, such as the pace of a metronome.

Value-Added Time—Time of those work elements that actually transform the product in a way that the customer is willing to pay for.

Value Analysis/Value Engineering—Value Analysis/Value Engineering (VA/VE) is a systematic method used to analyze and improve value in a product, design, system, or service.

Value Stream Map (VSM)—A diagram of every step involved in the material and information flows needed to bring a product from order to delivery.  Often used to help highlight major opportunities, and includes a value-added/non-value-added ratio.

Visual Management—The placement of all tools, parts, activities, and indicators of production system performance, so the status of the system can be understood at a glance by everyone involved. (See also: Andon, Jidoka)

Work-in-Process (WIP)—Items of work between processing steps.

X-Matrix—A template in which the organization’s strategic plans, key activities and metrics/targets are listed. (See also: Hoshin Kanri.)

Yokoten—The Japanese term for deploying concepts, ideas, or policies horizontally across the company.  Example: If a defective valve is found on one machine in a facility, yokoten would be the process to ensure that all similar valves in the facility (and other relevant facilities) are also examined for the same defect.