Lean Solutions Glossary
5Ss - Refers to the five Japanese words: seiri, seiton, seiso, seiketsu, and shitsuke which are shorthand expressions for the principal techniques of maintaining an effective, efficient workplace. Some companies add a 6S, Safety. A brief explanation of these terms follows:
- Seiri (Sort): Eliminating everything not required for the work being performed.
- Seiton (Straighten): The efficient placement and arrangement of equipment and material.
- Seiso (Shine): Maintaining tidiness and cleanliness in the workplace.
- Seiketsu (Standardize): An ongoing, standardized, improvement process.
- Shitskue (Sustain): Discipline with leadership.
5 Whys - A simple technique used to reveal the root cause (as opposed to the symptoms) of a problem. This approach asks the question "why" until the root cause is finally discovered.
Andon Board - A visual control device in a production area. It is typically a lit overhead display, giving the current status of the production system and alerting employees to emerging problems. The number of lights and their possible colors can vary. However, the traditional colors and their meanings are:
- Green - No problems
- Yellow - Situation requires attention
- Red - Production stopped; attention urgently needed
ANOVA - An abbreviation of analysis of variance.
Autonomation - Automation with a human touch. A partial English translation of jidoka.
Cellular Manufacturing - An approach in which manufacturing work centers (cells) have the total capability necessary to produce an item or group of similar items.
Continuous Flow Manufacturing (CFM) - Descriptive of material moving one piece at a time, at a rate determined by the needs of the customer, in a smooth and uninterrupted sequence, without WIP.
CPM - An event oriented, project planning technique meaning critical path method.
CTQ Tree - A tool to translate initial customer requirements into numerical or quantified needs for a product or service.
Cycle Time - The normal time to complete a product or service operation. This is not the same as takt time.
DFSS - An acronym meaning design for six sigma.
DFX - An acronym meaning design for X, where X represents an attribute such as service, assembly, or manufacture.
DMAIC - The core problem solving methodology used by many lean six sigma companies. The term refers to the steps: define, measure, analyze, improve, and control.
DPMO - An acronym meaning defects per million opportunities.
DPO - An acronym meaning defects per opportunity.
DPU - A term meaning defects per unit.
Enterprise Resource Planning (ERP) - ERP adapts the techniques of MRPII to all areas of an organization (as opposed to the manufacturing arena). ERP is usually implemented as a comprehensive business software solution.
Error-proofing - A technique for preventing production errors by designing the manufacturing process, equipment, and tools so that an operation literally cannot be performed incorrectly (see poka-yoke).
EVOP - Stands for evolutionary operations in experimental design.
Flexible Manufacturing Systems (FMS) - An integrated manufacturing capability to produce small numbers of a great variety of items at low unit costs. A FMS is also characterized by low change over time and rapid response times.
FMEA - A design review process referring to failure mode effect analysis.
FMECA - A design review process referring to failure mode effect criticality analysis.
FPY - A product yield term meaning first pass yield.
Gannt Charts - A form of bar chart used to display project planning activities.
Gemba - The shop floor or work site.
Heijunka - A production scheduling/leveling tool, essentially used to distribute kanban cards in an efficient manner.
Hoshin Planning - A management policy or strategy deployment approach. A method for establishing goals (and supporting policies) and ensuring that they are the primary focus of the organization.
Inventory Turns - The number of times inventory is consumed in a given period.
Jidoka - A form of automatic inspection of each item produced. Production is halted and workers are notified, if a defect is detected. Toyota expands the meaning of jidoka to include the responsibility of all workers to function in a similar manner.
Just-in-Time (JIT) - A production scheduling concept that calls for any items needed at a production operation (whether raw material or finished item) to be produced and available precisely when needed (not earlier or later).
Kaizen - The philosophy that every process can and should be continually evaluated and improved in terms of the time required, resources used, resultant quality, etc.
Kanban - A card or sheet used to authorize production or movement of an item. When fully implemented, kanban operates according to the following rules:
- All production and movement of parts and material takes place only as required by a downstream operation.
- The specific tool which authorizes production or movement is called a kanban. This word means card or sign, but can refer to containers or devices.
- The quantity authorized per individual kanban is minimal, ideally one. The number of circulating kanban for an item is determined by the demand rate for the item and the time required to produce or acquire it.
Kano Model - A methodology to analyze customer needs by considering dissatisfiers, satisfiers, and delighters.
KPIV - Stands for key process input variables.
KPOV - Stands for key process output variables.
Lean Enterprise - The efficient performance of all aspects of an organization, from the beginning of the supply chain, thru the production process, including the customer base.
Lean Manufacturing - The philosophy of continually reducing waste in all areas and in all forms. This English phrase often refers to the Toyota production system.
Level Loading - The smoothing or balancing of the work load in all steps of a process.
Line Balancing - The equalization of the cycle times for units of the manufacturing process, through the proper assignment of workers and machines to ensure smooth production flow.
Mistake-proofing - A manufacturing technique for providing a signal when an error is about to be introduced into the production process. This can be as simple as the use of a checklist.
MRP/MRPII-Material Requirements Planning - A technique (usually augmented with software) for planning production material requirements, based on historic usage, historic production, delivery lead times, and economic order size costing. MRPII software programs have the added capability for capacity planning, scheduling, and shop floor control. The scheduling and shop floor components of MRPII are often unreliable (unless perfect forecasts are available) and tend to introduce huge overhead costs in terms of inventory and production lead times.
Muda (waste) - A Japanese term meaning any activity that consumes resources but creates no value. Those activities and results that should be eliminated. Many references cite the following seven categories of waste:
- Excessive or early production
- Most movement and transport
- Poor process design
- Most inventory
- Inefficient performance of a process
- Making defective items
Mura - Inconsistency or variation.
Nagara - A smooth production flow, ideally one piece at a time, characterized by synchronization (balancing) of production processes and maximum utilization of available time. This includes overlapping operations where practical.
Nemawashi - Lining up your ducks. (A little humor)
Non-Value-Added - Those actions that the customer is not willing to pay for. Any activity that does not add value to the production or service.
NPV - An acronym representing net present value. This calculation considers cash flow, time, and interest rates.
One Piece Flow - The concept of reducing production batch sizes to a minimal amount, preferably a single unit. This can have dramatic effects on raw material, WIP, finished goods inventories, production lead times, quality, and costs.
PDCA - A general problem solving methodology representing the steps: plan, do, check, and act.
PDSA - Deming's modified problem solving methodology representing the steps: plan, do, study, and act.
Perfection - The complete elimination of muda so that all activities, along a value stream, create value.
PERT - An event oriented, project planning technique meaning program evaluation and review technique.
Point of Use Inventory - Inventory that is delivered to the location where it will be consumed.
Poka-Yoke (Mistake-proofing) - A means of providing a visual or audible signal to indicate a characteristic state. Often referred to as "error-proofing", poka-yoke is actually the first step in truly error-proofing a system.
Pull System - A manufacturing planning system based on the communication of actual real-time needs from downstream operations. A pull system is in contrast with push systems, which schedule operations according to theoretical downstream results, based "best-guess" planning, MRP, or other methods.
Queue Time - The time a product spends awaiting the next processing step.
ROA - A financial and project analysis term meaning return on assets.
ROI - A financial and project analysis term meaning return on investment.
RTY - A product yield term meaning rolled through-put.
Seiban - Seiban is the name of a Japanese management practice taken from the Japanese words "sei", which means manufacturing, and "ban", which means number. A Seiban number is assigned to all parts, materials, and purchase orders associated with a particular customer's job or project. This enables a manufacturer to track progress.
Sensei - One who provides information; a teacher or instructor.
Setup Time - The time required to change over a machine or process from one item or operation to the next item or operation. This time can be divided into two types:
- Internal: Setup work that can be done only when the machine or process is not actively engaged in production.
- External: Setup work that can be done concurrent to normal operations.
Shojinka - Continually optimizing the number of workers in a work center to meet the type and volume of demand imposed on the work center. Shojinka requires workers trained in multiple disciplines and a supportive work center layout (such as U-shaped or circular).
Single Piece Flow - A situation in which one complete product proceeds through various operations like design, order taking, and production, without interruptions, back flows, or scrap. This is in contrast with batch and queue arrangements.
SIPOC - A term implying a high-level process map focusing on suppliers, inputs, processes, outputs, and customers.
Six Sigma - A concept that implies a highly disciplined approach to deliver near-perfect products and services on a consistent basis. The value originates from a + 4.5 sigma that accomplishes a + 1.5 sigma shift over time.
Skills Matrix - A work cell visual control depicting all work activities. It provides assistance in the cross-training of team members.
Small Lot Principle - Effectively reducing lot size until the optimum of one piece flow is realized.
SMED (Single Minute Exchange of Die) - Literally means changing a die on a machine in a minute or less. Often, the key to doing this is by converting internal setup time to external setup time. One common variation of SMED is the single digit setup, which requires performing a setup activity in a single digit number of minutes (fewer than ten).
Standard Work - A precise description of each work activity, specifying cycle time, takt tame, the work sequence of specific tasks, and the minimum inventory of parts needed to conduct the activity.
Takt Time - Takt time is the available production time divided by the rate of customer demand. For example, if customers want 480 widgets per day and the factory operates 960 minutes per day, the takt time is two minutes. Takt time becomes the heartbeat of any lean organization. Takt is a German term for rhythm. Takt time is the rate at which customers demand a product and is not the same as cycle time.
Triage - A system used to sort workloads into categories in a service environment. This method facilitates prioritization of the workloads by urgency, level of difficulty, or length of activity, to reduce delays in performing the service.
TRIZ - A Russian abbreviation for the "the theory of inventive problem solving." The term is pronounced "trees". It consists of 9 action steps and some 40 basic principles.
Value - From the perspective of the customer, value represents those aspects or features of products or services that they are willing to pay for.
Value-Added - Those steps that transform raw materials or activities directly into the features for which the customer assigns value.
Value Stream - The specific activities required to design, and provide a specific product, from concept to launch, from order to delivery.
Visual Control - The placement, in plain view, of all the tools, parts, production activities, and indicators or production system performance, such that the status of the system can be easily and quickly understood.
VOC - A term meaning an activity to hear the voice of the customer.
Waste - All overproduction ahead of demand, waiting for the next processing step, unnecessary transport of materials, excessive inventories, unnecessary employee movements, and production of defective parts.
Water Spider (mizusumashi) - An individual who performs a wide range of tasks which allow other workers to perform value-added tasks.
WBS - An acronym meaning work breakdown structure. This activity expands an improvement project into a detailed listing of activities.
WCM (World Class Manufacturing) - The philosophy of being the best, the fastest, and the lowest cost producer of a product or service in order to remain an industry leader.
WIP (Work-in-Process) - Inventory that exists (in batches) between workstations.
Work Cell - The layout of machines or business processes of different types, performing different operations in a tight sequence, (typically a U-shape or L-shape), to permit single piece flow and flexible deployment of human effort.
Work Center - One process station in a work cell.