This glossary of terms used in quality, Six Sigma, ISO, and Lean was developed from many sources specifically for the use of Continuous Improvement Conference attendees.
Eliminates waste through product and process design. It meets customer requirements by starting with a clean product development slate to rapidly create and test potential product and process designs that require the least time, material, and capital resources.
5S (Sort/Set in order/Shine/Standardize/Sustain)
Used by front-line workers to organize the workplace. Improves workplace safety, reduce waste, simplify work processes, improve equipment maintenance and trouble-shooting, and ensure product quality.
6σ (Six Sigma)
Seeks to improve the quality of process outputs by identifying and removing the causes of defects and minimizing variability in manufacturing and business processes.
8D (Eight Disciplines) Problem Solving Process
The eight disciplines are:
- Use a Team.
- Define the Problem.
- Implement and verify Interim Actions.
- Identify and Verify Root Causes.
- Implement and validate PCAs.
- Prevent recurrences.
- Congratulate your Team.
Being able to see and quickly take action to correct abnormalities.
Instrument accuracy is the difference between the observed average value of measurement on a test piece or process, and the master value for the same test piece or process.
Activity Based Management (ABM)
Activities managed based on ABC costing.
Activity Based Costing (ABC)
A management accounting system that assigns cost to products based on the resources used to perform a process.
A “Visual Indicator” device that indicates the “Status” of a machine, line, or process. Frequently audible alarms or warning messages accompany Andon status lights as a secondary method of communicating a problem has arisen. Andons are typically color-coded with these generic colors:
– Green (normal operations)
– Yellow (not running at rate, help needed, or in midst of changeover or planned maintenance)
– Red (a problem occurred, the machine or line is stopped, and urgent attention is needed)
Analysis of Variance – a basic statistical technique for analyzing experimental data.
Annual Operating Plan – Basically plan that a site/SBU/SBE is measured to.
Acceptance Quality Level – when a continuing series of lots is considered, a quality level that, for the purposes of sampling inspection, is the limit of a satisfactory process average.
Based on the principles of Edward Deming’s PDCA (Plan-do-Check-Act) cycle, A3 is a structured problem solving methodology which is known for putting all the information relative to the problem on a single piece of paper (11×17). It provides a consistent and common approach to solving problems throughout organizations which helps to embed a robust business problem solving culture.
Qualitative data that can be counted for recording and analysis. These include characteristics of occurrence, or number of times/parts installed per cycle, etc.
Personnel responsible for area or activity being audited.
Automatically decrement perpetual inventory records, based on the bill of materials of a given product.
When a manufacturing system produces exactly what a company’s customers demand. All operations or cells produce at the same cycle time. In a balanced system, the cell cycle time is less than the takt time. Production rates above or below takt time are considered not “in balance” with customer demand.
The process of producing more than one piece of an item (a batch) before they are actually needed by the customer. When the batch is transferred to a downstream process, it sits in line (the queue) waiting to be processed.
A philosophy that rejects batch, lot, or mass processing as wasteful. Product should move (flow) from operation to operation only when it is needed, in the smallest increment, one piece being the ultimate.
The process of measuring products, services, and practices against those organizations known to be leaders in one or more aspects of their operations.
Trained in Six Sigma and Lean principles, Black Belts lead teams responsible for measuring, analyzing, improving, and controlling key processes that influence customer satisfaction and/or productivity growth. Black belts train and coach project teams and are full-time positions.
A blitz is a fast and focused process for improving some component of business: a product line, a machine, or a process. It utilizes a cross-functional team of employees for a quick problem-solving exercise, where teams focus on designing solutions to meet some well-defined goals.
The slowest operation (choke point) in a manufacturing process. Do not confuse this with a company’s “constraint” taken from TOC (Theory of Constraints), which is the slowest operation in an entire manufacturing system that, if remedied, would increase overall company throughput.
Comparison of a measurement standard or instrument of known accuracy with another instrument to detect, correlate, report, or eliminate by adjustment any variation in the accuracy of the item being compared to minimize errors.
Corrective Action Request (CAR)
A form used in internal auditing to notify a department of non-conformances in a quality system.
A Lean system to improve bi-directional feedback and ownership especially for complex decision making and policy deployment. Playing “catchball” ensure that everyone who should give input, at all levels, does. It ensure that everyone is committed to doing what everyone agreed to.
Cause and Effect Diagram
A visual problem-solving tool used to logically organize possible causes for a specific problem or effect by graphically displaying them in increasing detail. It helps to identify root causes and ensures common understanding of the causes. Also called an Ishikawa Diagram.
Generally a horseshoe or U-Shaped work area layout that enables workers to easily move from one process to another in close proximity and pass parts between workers with little effort. “Cells” typically focus on the production of specific models in “part families,” but can be adjusted to many different products as needed.
Switching from producing one part/product to another, which could include installing a new plate in a printing unit of a press, new ink in the ink fountain, new software in a computer, and so on.
A source of variation that is always present; part of the random variation inherent in the process itself. Its origin can usually be traced to an element of the system which only management can correct..
Taken from the theory of constraints (TOC), a constraint is anything that limits a system from achieving higher performance versus its goal.
Moving products through a production system without separating them into lots or batches. Once you begin producing a product you keep it moving through the value stream without placing it into a holding area for later processing. This helps avoid “batching” and increasing inventory levels.
Follows a “Plan-do-check-act” cycle.
Control charts show how a process changes over time. It is a graphical tool for monitoring changes that occur within a process, by distinguishing variation that is inherent in the process (common cause) from variation that shows a change to the process (special cause). This change may be a single point or a series of points in time—each is a signal that something is different from what was previously observed and measured.
A line (or lines) on a control chart used as a basis for judging the significance of the variation from subgroup to subgroup. Control limits reflect the expected variation in the data. Variation beyond a control limit is evidence that special causes are affecting the process. Control limits are calculated from process data and are not to be confused with engineering specifications.
Actions taken to eliminate the cause of a detected nonconformance within a product, service, or quality management system and those measures taken by management to prevent its recurrence.
CTQ: Critical To Quality
CTQs are the internal critical quality prThe element of a process or practice which has a direct impact on its perceived quality.
Current State Map
A value stream map of the process as it is currently being done in order to identify opportunities for reducing non-value-added activities and other sources of waste.
The time it takes to do one repetition of any particular task typically measured from “start to start,” the starting point of one product’s processing in a specified machine or operation until the start of another similar product’s processing in the same machine or process. Cycle time is commonly categorized into:
- Manual Cycle Time: The time loading, unloading, flipping/turning parts, adding components to parts while still in the same machine/process etc.
- Machine Cycle Time: The processing time of the machine working on a part.
- Auto Cycle Time: The time a machine runs un-aided (automatically) without manual intervention.
- Overall Cycle Time: The complete time it takes to produce a single unit. This term is generally used when speaking of a single machine or process.
- Total Cycle Time: This includes all machines, processes, and classes of cycle time through which a product must pass to become a finished product. This is not Lead Time, but it does help in determining it.
A set of metrics, usually not more than five or six, that provides an “at-a-glance” summary of an organization’s or project’s status. Every participant in an organization/project—from the CEO to a factory floor worker—can have his or her own dashboard with function- and level-appropriate data summaries.
A defect is a frailty or shortcoming in a product resulting from a departure from its design specifications during production.
Design For Six Sigma (DFSS)
DFSS is a systematic methodology utilizing tools, training, and measurements to enable companies to design products and processes that meet customer expectations and can be produced at Six Sigma quality levels.
An audit which is conducted of documentation only. These determine that all elements of the quality system are documented and compliant with the requirements of ISO 9001, but do not address implementation.
Detection or inspection is a part-oriented strategy that attempts to identify unacceptable output after it has been produced and to separate it from the good output.
A distribution describes a population from which observations are drawn, categorized into cells and forming identifiable patterns. It is based on the concept of variation that states that anything measured repeatedly will arrive at different results. These results will fall into statistically predictable patterns. A bell-shaped curve (or normal distribution) is an example in which the greatest number of observations fall in the center with fewer and fewer observations falling evenly on either side of the average.
The tendency of large numbers of observations to group themselves around some central value with a certain amount of variation or “scatter” on either side.
A Six Sigma structured problem solving methodology: define, measure, analyze, improve, and control.
Activities which ensure that the review, approval, issuance, amendment, retrieval, storage, and destruction of documentation and data are performed, providing recipients with only approved documents of the latest revision at all locations where they apply.
DOE: Design of Experiments
DOE is a family of statistical improvement techniques.
Taiichi Ohno’s original seven wastes typically found in mass production:
- Overproduction—producing ahead of customer or next process demand
- Waiting—operators standing idle waiting for the next processing stop
- Transportation—unnecessary transport of materials
- Overprocessing—performing unnecessary or incorrect processing due to poor tool and product design
- Inventory—having more than the absolute minimum inventory needed
- Motion—unnecessary movement by employees during the course of their work
- Defects—production of defective parts.
An eighth waste is commonly recognized as underutilized resources or human imagination.
Enterprise Resources Planning (ERP)
Taking the needs of an entire organization into account, ERP is essentially an extension of Manufacturing Resources Planning (MRP) that attempts to ascertain needs and abilities of a company system. ERP allows companies to standardize their data, streamline the analysis process, and manage long-term business planning with greater ease.
Error & Mistake-Proofing (a.k.a. Poka-Yoke)
A manufacturing technique of preventing errors by designing the manufacturing process, equipment, and tools so that an operation literally cannot be performed incorrectly.
People or organizations who receive and pay for a product, a service, or information.
Setup procedures that can be performed while the machine is in motion.
A systematic/structured approach for determining the seriousness of potential failures and for identifying the sources of each potential failure. The goal of FMEA is to identify potential failures and implement corrective actions to prevent failures from occurring. “PFMEA” focuses on identifying and remediating process failures.
A method of workplace organization and visual controls developed by Hiroyuki Hirano. It is a structured and disciplined method of organizing and running the workplace—factory, office, or service sector activity—for improved productivity, safety, and quality at reduced cost and higher efficiency. The five terms starting with “S” are:
- Sort means to separate needed tools, parts, and instruction from unneeded materials and to remove the latter.
- Set-in-order means to neatly arrange and identify parts and tools for ease of use.
- Shine means to conduct a cleanup campaign.
- Standardize means to conduct sort, simplify, and scrub activities at frequent intervals to maintain a workplace in perfect condition.
- Sustain means to form the habit of always following the first four steps.
|Japanese “S”||American “S”|
|Seiton (Tidiness)||Set in order|
A main objective of the Lean production effort, and one of the important concepts that passed directly from Henry Ford to Toyota. Ford recognized that, ideally, production should flow continuously all the way from raw material to the customer and envisioned realizing that ideal through a production system that acted as one long conveyor.
Force Field Analysis
A technique, developed by Kurt Lewin, for analyzing what aids or hinders an organization in reaching an objective. An arrow pointing to an objective is drawn down the middle of a piece of paper. The factors that will aid the objective’s achievement, called the “driving forces,” are listed on the left side of the arrow. The factors that will hinder its achievement, called the “restraining forces,” are listed on the right side of the arrow.
A statistical table that presents a large volume of data in such a way that the central tendency (average/mean/median) and distribution are clearly displayed.
The practice of grouping machines or activities by type of operation performed.
Future State Map
A blueprint for lean implementation. Your organization’s vision, which forms the basis of your implementation plan by helping to design how the process should operate. The future state map deploys the opportunities for improvement, identified in the current-state map, to achieve a higher level of performance at some future point.
This is a statistical tool that measures the amount of variation in the measurement system from the device used, the people taking the measurement, the interaction between the device and the person, and the error seen from the parts.
GB or GBC
Green Belt or Green Belt Candidate.
Green Belts are trained on basic Six Sigma improvement methodology and will lead a process improvement or quality improvement team as part of their full-time job. Green Belts are coached by Black Belts.
A method of leveling production at the final assembly line that makes just-in-time production possible. This involves averaging both the volume and sequence of different model types on a mixed-model production line. Heijunka is crucial to avoid excessive batching.
A chart that displays data in distribution, generally in graph format. It may be used to reveal the variation that any process contains.
Hosin Kanri or Planning (HP)
Hoshin Kanri methodology ensures that everyone in the organization knows the strategic direction of the company. Creating a working communication system means everyone is working toward a common goal. Also known as Management by Policy or Policy Deployment. Goals are established and measures are created to ensure progress toward those goals. HP keeps activities at all levels of the company aligned with its overarching strategic plans. HP typically begins with the “visioning process,” which addresses the key questions: Where do you want to be in the future? How do want to get there? When do you want to achieve your goal? And who will be involved in achieving the goals? HP then systematically explores the whats, whos, and hows throughout the entire organization.
Stands for Interclass Correlation Coefficient, a reliability index that allows you to see how well defined a subjective measurement system is when a ranked scaling is being used.
Individual X Moving Range Chart. Looks at one piece samples on a Control Chart.
Area within which you draw conclusions (e.g., based on the results of a DOE).
Interclass Correlation Coefficient
A reliability coefficient that is used to judge the reproducibility of a subjective measurement system for attribute data that is ranked. One type of MSA.
One of the 8 Wastes. All raw materials, purchased parts, work-in-process components, and finished goods that are not yet sold to a customer.
Inspection, Measuring And Test Equipment
All equipment used to measure, gauge, test, inspect, or otherwise examine items to determine compliance with specifications.
Employees or departments who receive output in the form of a product, a service, or information from other employees or departments within the organization.
Internal Quality Audit
A documented activity performed to verify, by examination of objective evidence, that applicable elements of the quality system are suitable and have been developed, documented, and effectively implemented in accordance with specified requirements.
International Organization For Standardization (ISO)
This is an independent non-governmental organization formed in 1946 in Geneva, Switzerland. ISO comes from the Greek word “isos” which means to be “the same.” It is a voluntary system that holds all companies to the same standards and must be certified by a third party.
The latest revision of the ISO standards pertaining to the requirements for a quality management system.
JIT is a system for producing and delivering the right items at the right time, in the right amounts. The key elements of JIT are flow, pull, standard work, and takt time. Principles that are fundamental to time-based competition include waste elimination, process simplification, set-up and batch-size reduction, parallel processing, and layout redesign. organization.
KAI (to modify, to change) + ZEN (think, make good, make better) = KAIZEN
Non-value-added waste (or “Muda”) exists everywhere, related to people, materials, facilities, and production set-up. Kaizen refers to the series of activities whereby instances of waste are eliminated one by one at minimal cost, by workers pooling their wisdom. The whole secret to Kaizen is to create an atmosphere, a culture of continuous improvement, by focusing people on problems. In short, Kaizen means continuous improvement through incremental improvement.
A Japanese term. The actual term means “signal”. It is one of the primary tools of a Just in Time (JIT) manufacturing system. It signals a cycle of replenishment for production and materials. This can be considered as a “demand” for product from one step in the manufacturing or delivery process to the next. It maintains an orderly and efficient flow of materials throughout the entire manufacturing process with low inventory and work in process. It is usually a printed card that contains specific information such as part name, description, quantity, etc.
A reliability coefficient that is used to judge the reproducibility of a subjective measurement system for attribute data that is non-ranked (ie good/bad, pass/fail…). This is one type of MSA.
The time that is required from receipt of order until shipped to the customer.
Business processes focused solely on providing customer-defined value while eliminating all waste activities associated with production and administration activities.
Balancing of Cycle Times at each operation to be less than or equal to Takt Time.
A measure of deviation from a linear relationship between two variables, or the issue of Linearity, where a measurement system has changing variation across its usable range of measure.
Lower Control Limit
A horizontal dotted line plotted on a control chart which represents the lower process limit capabilities of a process. The line is set at 3 standard deviations from the mean which represents the expected variation in the data.
An award established by the U.S. Congress in 1987 to raise awareness of quality management and recognize U.S. companies that have implemented successful quality management systems. Awards can be given annually in six categories: manufacturing, service, small business, education, healthcare and nonprofit. The award is named after the late Secretary of Commerce Malcolm Baldrige, a proponent of quality management. The U.S. Commerce Department’s National Institute of Standards and Technology manages the award, and the American Society of Quality (ASQ) administers it.
Master Black Belt
Master Black Belts are Six Sigma Quality experts that are responsible for the strategic implementations within an organization. A Master Black Belt’s main responsibilities include training and mentoring of Black Belts and Green Belts; helping to prioritize, select and charter high-impact projects; maintaining the integrity of the Six Sigma measurements, improvements and tollgates; and developing, maintaining and revising Six Sigma training materials.
Variation in measurements that can be attributed to variation in the item being measured or in the measurement system itself.
Methods that help operators avoid mistakes in their work caused by choosing the wrong part, leaving out a part, installing a part backwards, etc. Also called mistake-proofing, poka-yoke (error-proofing) and baka-yoke (fool-proofing).
Mixed Model Production
Capability to produce a variety of models, that differ in labor and material content, on the same production line. Allows for efficient utilization of resources while providing rapid response to marketplace demands.
The Japanese for waste; any activity that consumes resources but creates no value for the customer.
Numerical Evaluation of Metrics – another name for control charting focusing on the idea rational subgrouping, that is using changing subgroups to evaluate a process.
A non-conformance means that something went wrong – a problem has occurred and needs to be addressed. Non-conformances are addressed with corrective actions.
Specific occurrences of a condition that does not conform to specifications or other inspection standards; sometimes called discrepancies or defects. An individual nonconforming unit can have the potential for more than one nonconformity. Generally a “c” or “u” chart is used to analyze systems producing nonconformities.
Activities or actions taken that add no real value to the product or service making such activities or action a form of waste.
Normal distribution is the spread of information (such as product performance or demographics) where the most frequently occurring value is in the middle of the range and other probabilities tail off symmetrically in both directions. Normal distribution is graphically categorized by a bell-shaped curve, also known as a Gaussian distribution. For normally distributed data, the mean and median are very close and may be identical.
In the simplest of terms, one-piece flow means that parts are moved through operations from step to step with no work-in-process (WIP) in between each piece. This system works best in combination with a cellular layout in which all necessary equipment is located within a cell in the sequence in which it is used.
Tactical details for short-term tied into Strategic Plans.
To manufacture an item before it is actually required. Overproduction is highly costly to a manufacturing plant because it prohibits the smooth flow of materials and actually degrades quality and productivity.
Focuses on efforts or the problems that have the greatest potential for improvement by showing relative frequency and/or size in a descending bar graph. Based on the proven Pareto principle: 20% of the sources cause 80% of any problems.
PDCA (Plan, Do, Check, Act)
The PDCA Cycle is a systematic series of steps for gaining valuable learning and knowledge for the continual improvement of a product or process. Also known as the Deming Wheel, or Deming Cycle, the concept and application was first introduced to Dr. Deming by his mentor, Walter Shewhart of the famous Bell Laboratories in New York.
Plan: This involves identifying a goal or purpose, formulating a theory, defining success metrics and putting a plan into action.
Do: The components of the plan are implemented, such as making a product.
Check: Outcomes are monitored to test the validity of the plan for signs of progress and success, or problems and areas for improvement.
Act: This step closes the cycle, integrating the learning generated by the entire process, which can be used to adjust the goal, change methods or even reformulate a theory altogether.
These four steps are repeated over and over as part of a never-ending cycle of continual improvement.
Point-Of-Use Storage (POUS)
What you need where you need it. All material is stored where it is going to be used in the process. POUS reduces material handling requirements and makes it easier to determine raw material needs due to smaller shipments from vendors.
Japanese approach to ‘mistake proofing‘ in all aspects of manufacturing, customer service, procurement, etc. It employs visual signals that make mistakes clearly stand out from the rest, or devices that stop an assembly line or process if a part or step is missed.
The universe of data under investigation from which a sample will be taken.
A future-oriented strategy that improves quality by directing analysis and action toward correcting the production process. Prevention is consistent with a philosophy of continuous or never-ending improvement.
Pro-active action taken to eliminate the cause(s) of a potential nonconformity or other undesirable or unsafe situation in order to prevent occurrence.
The combination of people, machine and equipment, raw materials, methods and environment that produces a given product or service.
The measured, built-in reproducibility or consistency of the product turned out by the process. Such a determination is made using statistical methods. The statistically determined pattern or distribution can only then be compared to specification limits to decide if a process can consistently deliver product within those parameters.
Process Failure Modes Effects Analysis (PFMEA)
PFMEA Is a systemized group of activities to (a) recognize and evaluate the potential failure of a product/process and its effects, (b) identify actions which could eliminate or reduce the occurrence, (c) document the process, and (d) track changes to the process to avoid potential failures.
The time a product actually is being worked on in design or production and the time an order actually is being processed. Typically, processing time is a small fraction of production lead time.
The cycle of continuous review, re-examination, and renewal of fundamental work processes that contribute to an organization’s performance and productivity. Itself a continual process, process management must at all times challenge a process’s fit with other processes, and may result a in radical change to work methods and practices.
A method of production control in which downstream activities signal their needs to upstream activities. Pull production strives to eliminate overproduction and is one of the three major components of a complete just-in-time production system. In pull production, a downstream operation, whether within the same facility or in a separate facility, provides information to the upstream operation, often via a kanban card, about what part or material is needed, the quantity needed, and when and where it is needed. Nothing is produced by the upstream supplier process until the downstream customer process signals a need.
One of the three elements of JIT. In the pull systems, the downstream process takes the product it needs and pulls it from the producer. This customer’s pull is a signal to the producer that the product is sold. The pull system links accurate information with the process to minimize waiting and overproduction.
In contrast to the pull system, product is pushed into a process, regardless of whether it is needed. The pushed product goes into inventory, and lacking a pull signal from the customer indicating that it has been bought; more of the same product could be overproduced and put in inventory.
Term that describes the condition which exists when a product’s performance and/or characteristics satisfy the stated or implied needs of the customer.
Quality Function Deployment (QFD)
A visual decision-making procedure for multi-skilled project teams which develops a common understanding of the voice of the customer and a consensus on the final engineering specifications of the product that has the commitment of the entire team. QFD integrates the perspectives of team members from different disciplines, ensures that their efforts are focused on resolving key trade-offs in a consistent manner against measurable performance targets for the product, and deploys these decisions through successive levels of detail. The use of QFD eliminates expensive backflows and rework as projects near launch.
Activities which include strategic planning, allocation of resources and systematic activities for quality assurance such as planning, operations, and evaluation. These activities are the responsibility of senior management.
A document that is a part of the ISO 9000 system that describes a company’s higher-level approach to the ISO standards and requirements for how it operates and does business.
An organization’s general statement of its beliefs about quality, how quality will come about, and its expected result.
All forms and records which exist as a result of a process and serves as evidence that the product meets the specified requirements. Records may be in the form of hard copy or electronic media.
The organizational structure, responsibilities, procedures, processes, and resources for implementing quality management.
Quality System Documents
Quality manual, system procedures manual, work instruction manual, and forms which are used to define the manner of production where their absence would adversely affect quality.
The time a product spends in a line awaiting the next design, order processing, or fabrication step.
The ability to change tooling and fixtures rapidly (usually minutes). In printing this normally relates to faster makereadies so more jobs can be run in the same amount of time.
A source of variation which is random. In this case, a change in the source (“trivial many” variables) will not produce a highly predictable change in the response (dependent variable), e.g., a correlation does not exist. Random variation cannot be economically eliminated from a process.
Random Effects Model
A situation where we want to extend the conclusions of a statistical test beyond the levels of the factors used in the test, the factors therefore must be random factor levels from a larger population of potential levels.
A measure of variation in a set of data. It is calculated by subtracting the lowest value in the data set from the highest value in the same data set.
Randomized Incomplete Block Design – Running a DOE with a block within one factors levels sets.
Root Cause Analysis
A problem solving methodology that focuses on resolving the underlying problem instead of applying quick fixes that only treat immediate symptoms of the problem. A common approach is to ask why five times – each time moving a step closer to discovering the true underlying problem. Root cause analysis helps to ensure that a problem is truly eliminated by applying corrective action to the “root cause” of the problem.
One or more individual events or measurements selected from the output of a process for the purpose of identifying characteristics and performance of the whole.
A team of individuals at the highest level of organizational management who have the day-to-day responsibilities of managing a company or corporation (owner, chief executive office, chief operating officer, president, vice president, and general manager.)
The Japanese term for “teacher”. An outside master or teacher that assists in implementing Lean practices. The sensei must be an easily understood and inspiring.
The seven wastes (muda) are activities identified and categorized as non-value adding events or processes that limit profitability in a company.
First identified by Taiichi Ohno of Toyota, the “seven Wastes” are as follows: (simplified)
1. Overproduction: Making more parts than you can sell.
2. Delay: Waiting for processing, parts sitting in storage, etc.
3. Transporting Parts/Materials: Moving parts to various storage locations, from process to process, etc.
4. Over-Processing: Doing more “work” to a part than is required.
5. Inventory: Committing money and storage space to parts not sold.
6. Motion: Moving parts more than the minimum needed to complete and ship them.
7. Making Defective Parts: Creating parts that cannot be sold “as is” or that must be reworked, etc.
The Greek letter s (sigma) refers to the standard deviation of a population. Sigma, or standard deviation, is used as a scaling factor to convert upper and lower specification limits to Z. Therefore, a process with three standard deviations between its mean and a spec limit would have a Z value of 3 and commonly would be referred to as a 3 sigma process.
Single Minute Exchange of Dies (SMED)
A series of techniques pioneered by Shigeo Shingo for changeovers of production machinery in less than 10 minutes. The long-term objective is always zero setup, in which changeovers are instantaneous and do not interfere in any way with continuous flow. Setup in a single minute is not required, but used as a reference. Enables manufacturing in smaller lots, reduces inventory, and improves customer responsiveness. Techniques include:
- Convert setup steps to be external (performed while the process is running)
- Simplify internal setup (e.g. replace bolts with knobs and levers)
- Eliminate non-essential operations
- Create standardized work instructions
Single piece flow can be described as an ideal state of efficient operations, where batch sizes and lot production are replaced by working on one product at a time. While not practical for operations with low processing times and correspondingly high change-over times (both values defined by takt time), it is nevertheless a Lean Manufacturing goal to achieve single piece flow in every operation possible.
Six Sigma is a methodology that provides businesses with the tools to improve the capability of their business processes. This increase in performance and decrease in process variation leads to defect reduction and vast improvement in profits, employee morale and quality of product.
- METRIC: 3.4 Defects Per Million Opportunities (DPMO). DPMO allows you to take complexity of product/process into account.
- METHODOLOGY: DMAIC/DFSS structured problem-solving roadmap and tools.
- PHILOSOPHY: Reduce variation in your business and make customer-focused, data driven decisions.
A source of variation that is intermittent, unpredictable, unstable, sometimes called an assignable cause. Usually evident by a point beyond the control limits.
A measure of the spread of the process output or the spread of a sampling statistic from the process, denoted by the Greek letter sigma (upper case Σ, lower case σ).
Establishing precise procedures for each operator’s work in a production process, based on three elements:
- Takt time, which is the rate at which products must be made in a process to meet customer demand.
- The precise work sequence in which an operator performs tasks within takt time.
- The standard inventory, including units in machines, required to keep the process operating smoothly.
Standardized work, once established and displayed at workstations, is the object of continuous improvement through kaizen. The benefits of standardized work include documentation of the current process for all shifts, reductions in variability, easier training of new operators, reductions in injuries and strain, and a baseline for improvement activities.
A quantitative condition which describes a process that is free of assignable/special causes of variation, e.g., variation in the central tendency and variance. Such a condition is most often evidenced on a control chart, i.e., a control chart which displays an absence of nonrandom variation.
Statistical Process Control
The use of statistical techniques such as control charts to analyze a process or its output so as to take appropriate action to achieve and maintain a state of statistical control and to improve the capability of the process.
Strategic Planning Process
Process whereby goals are set through internal and external assessment and deployed to resources for performance and improvement activities.
The process of classifying data into subgroups based on characteristics or categories.
A condition where gains made in one activity are offset by losses in another activity or activities, created by the same actions creating gains in the first activity.
Individual or company providing products or services.
The German word for pace or rhythm. Used in Lean as the rhythm of the plant; i.e., if the customer wants a part every 30 seconds, the plant (or the Lean cell) should feel the heart beat of producing a part every 30 seconds.
The pace of production (e.g. manufacturing one piece every 34 seconds) that aligns production with customer demand. Calculated as planned production time divided by customer demand. This helps provide a simple, consistent and intuitive method of pacing production. Is easily extended to provide an efficiency goal for the plant floor (actual pieces divided by target pieces).
To calculate, take total available production time divided by the customer and requirement. Note: Include all demand planned activities such as clean-up, safety meetings, etc.
(1) 8 Hour Shift = 480 Minutes – (2) 10 Minute Breaks=460
1840 Pieces/Day Customer Requirements
TAKT Time = 0.25 minutes or 15 seconds
Theory of Constraints (TOC)
A management philosophy and a set of tools for organizational change developed by Israeli physicist Dr. Eliyahu Goldratt and popularized in the 1984 book The Goal by Goldratt and Jeff Cox. TOC concentrates on improving profits by managing constraints, factors that prevent a company from achieving its goals. Its primary focus is on removing or managing constraints to improve throughput, while Lean focuses on the identification and removal of waste to improve the flow of value. Both Lean and TOC emphasize improving the whole system rather than individual parts.
The time required for a product to proceed from order to delivery. When a scheduling and production system is running at or below capacity, throughput time and lead time are the same. When demand exceeds the capacity of a system, there is additional waiting time before the start of scheduling and production, and lead time exceeds throughput time.
Total Productive Maintenance (TPM)
A set of techniques, originally pioneered by Denso in the Toyota Group in Japan, to ensure that every machine in a production process always is able to perform its required tasks.
The approach is termed total in three senses. First, it requires the total participation of all employees, not only maintenance personnel but line managers, manufacturing engineers, quality experts, and operators. Second, it seeks total productivity of equipment by focusing on all of the six major losses that plague equipment: downtime, changeover time, minor stops, speed losses, scrap, and rework. Third, it addresses the total life cycle of equipment to revise maintenance practices, activities, and improvements in relation to where equipment is in its life cycle.
Unlike traditional preventive maintenance, which relies on maintenance personnel, TPM involves operators in routine maintenance, improvement projects, and simple repairs. For example, operators perform daily activities such as lubricating, cleaning, tightening, and inspecting equipment.
Total Quality Management
A management approach in which all departments, employees, and managers are responsible for continuously improving quality so that products and services meet or exceed customer expectations. The Total Quality Control (TQC) methodology relies on the plan-do-check-act (PDCA) cycle to manage processes and, when problems arise, statistical tools to solve them. The methodology and tools are used often by employees during kaizen activities and together form an important subsystem of Lean.
The patterns in a run chart or control chart that feature the continued rise or fall in a series of points. Like runs, attention should be paid to such patterns when they exceed a predetermined number.
A horizontal line on a control chart (usually dotted) which represents the upper limits of process capability. The line is set at 3 standard deviations from the mean which represents the expected variation in the data.
A product or service provided to a customer at the right time at an appropriate price, as defined in each case by the customer. In Lean thinking, an activity or process has value to a customer only if it is willing to pay for it.
A total package of products and services that we offer to customers. This package includes competitive cost, excellent service, and high product quality to ensure high customer satisfaction and retention.
A simple diagram of every step involved in the material and information flows needed to bring a product from order to delivery. Value-stream maps can be drawn for different points in time as a way to raise consciousness of opportunities for improvement. A current-state map follows a product’s path from order to delivery to determine the current conditions. A future-state map deploys the opportunities for improvement identified in the current-state map to achieve a higher level of performance at some future point.
In some cases, it may be appropriate to draw an ideal-state map showing the opportunities for improvement by employing all known Lean methods including right-sized tools and value-stream compression.
Characteristics of a part which can be measured such as length, id/od, width, etc.
Variation is the inevitable fluctuation in process output. It is quantified by standard deviation, a measure of the average spread of the data around the mean. The sources of variation are grouped into two major classes: common causes and special causes.
Systems that enable anyone to immediately assess the current status of an operation or process at a glance, regardless of their knowledge of the process. Visual displays relate information and data to employees in an area through the use of charts, graphs, and process documentation.
Any activity that consumes resources but creates no value for the customer. Most activities are waste—muda—and fall into one of two types. Type one muda creates no value but is unavoidable with current technologies and production assets. An example would be inspecting welds to ensure they are safe. Type two muda creates no value and can be eliminated immediately. An example is a process with disconnected steps in process villages that can be quickly reconfigured into a cell where wasteful materials movements and inventories no longer are required.
Analyzing the physical layout of a process flow with the intent of reducing travel distances, eliminating redundancies, improving communication and quality.
Work In Progress (WIP)
Material that has entered the production process, but is not yet a finished product. Work in progress (WIP) therefore refers to all materials and partly finished products that are at various stages of the production process. WIP excludes inventory of raw materials at the start of the production cycle and finished products inventory at the end of the production cycle. Also referred to as “work in process.”
Workplace Organization (5S)
Workplace Organization is the powerful combination of two Lean tools: 5S and Visual Management. A 5S system is used to identify and eliminate waste that causes searching for tools, equipment, information, etc. The 5S principle is “a place for everything, and everything in its place.” Visual controls are a series of techniques used to allow anyone to differentiate between a normal and an abnormal situation. The purpose of implementing visual controls is to manage a production process.
A Yellow Belt typically has a basic knowledge of Six Sigma, but does not lead projects on their own, as does a Green Belt or Black Belt. Is often responsible for the development of process maps to support Six Sigma projects. A Yellow Belt participates as a core team member or subject matter expert (SME) on a project or projects. In addition, Yellow Belts may often be responsible for running smaller process improvement projects using the PDCA (Plan, Do, Check, Act) methodology. PDCA, often referred to as the Deming Wheel, enables Yellow Belts to identify processes that could benefit from improvement. These smaller Yellow Belt projects often get escalated to the Green Belt or Black Belt level where a DMAIC methodolgy is used to maximize cost savings using Statistical Process Control.
Produced product compared to scheduled product.