Lean is the term coined to describe the manufacturing and organizational process that Toyota and other Japanese manufacturers have used to fundamentally change the automotive industry. Lean has proven just as effective, if not more, in a variety on different settings including Healthcare, Service industries and Transportation.
Lean is best characterized as a systematic approach to the identification and elimination of Waste or Non-value Added activities through continuous improvement.
3P: Production Preparation Process. Designing both the product and the production process based on Voice of Customer and Value Engineering principles to create products that are 'Lean' both in design and production methods. This exercise includes realizing seven alternatives.
4M's of Production: Member, Machine, Material, and Method. Understand these factors and the establishment of standards is key steps in strengthening the production processes.
5 WHY's: A method of evaluating a problem or question by asking Why and answering Why five times, which gets to root cause of the problem so that effective countermeasures can be developed.
6S: The principles of waste elimination through workplace organization. They are:
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7 Wastes: There are seven wastes that describe all wasteful activity in a production environment. Elimination of the 7 wastes leads to improved profits. They are
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80/20: A minority of causes, inputs, or effort usually lead to a majority of the results, outputs, or rewards. Without using the 80/20 principal to prioritize what we work on, four-fifths of our efforts will gain very little results.
Andon: A tool of visual management, originating from the Japanese word for 'lamp'. Most commonly andons are lights placed on machines or on production lines to indicate operation status. Andons are commonly color-coded green (normal operations), yellow (changeover or planned maintenance), and red (abnormal, machine down). Often combined with an audible signal such as music or alarms.
Autonomation: Giving the 'human touch' to automated machinery so machines are able to detect and prevent defects and immediately stop themselves while asking for help. This concept is also known as jidoka.
Automatic Time: The time when a machine is running on auto cycle and a person does not need to be there to operate the machine.
Benchmarking: Comparing key performance metrics with other organizations in similar or relevant industries. Establishing standards for improvement based on what others have been able to achieve. Visiting or interviewing peers to learn from what they have been able to accomplish.
Bottleneck: A process in any part of a company (office, production, sales, etc.) that limits the throughput of the whole process.
Cell: The layout of machines of different types performing different operations in a tight sequence, typically a u-shape, to permit one piece flow and flexible deployment of human effort by means of multi-machine working.
Chaku-Chaku: A method of conducting one piece flow in which the operator proceeds from machine to machine, taking the part from the previous operation and loading it into the next machine, then taking the part just removed from that machine and loading it into the following machine, etc. Literally means load-load in Japanese.
Changeover: The installation of a different type of tool in a process to produce a different type, or size of product. Often times batches of parts are produced to keep downstream processes supplied with parts while changeovers occur.
Counterclockwise Flow: A basic principle of Lean manufacturing cell layout is that the flow of material and the motion of people should be from right to left, or counterclockwise. The origin of this idea came from the design of lathes and machine tools with the chucks on the left side, making it easier for right-handed people to load from right to left.
Cycle Time: The time it takes to do one repetition of any particular task. Cycle time can be categorized into 1) manual cycle time, 2) machine cycle time, and 3) auto cycle time.
Elements of Work: The elements of work are 1) value-added work, 2) non value-added work. Non value-added work is something the customer is not willing to pay for.
External Set-Up: All set-up tasks that can be done while the machine is still running. Examples are collecting tools, the next piece of material, preparing or fixtures. Moving set-up activities from internal to external in order to reduce machine down time is a central activity of set-up reduction and SMED (see SMED Single Minute Exchange of Dies).
First In First Out: Also known as FIFO, a system of keeping track of the order in which information or materials need to be processed. The goal of FIFO is to prevent earlier orders from being delayed unfairly in favor of new orders.
Flow: One of the 3 elements of JIT, flow production is defined as moving the product or information from one value-added step to the next continuously.
Gemba: Japanese for 'actual place' or 'the place where it happens'. In manufacturing, the gemba is the shop floor. The gemba is where the value is created.
Hanedashi: Auto-eject devices that unload the part from the machine once the cycle is complete. This allows the operators to go from one machine to the next without waiting, picking up and loading parts. Hanedashi is a key component of chaku-chaku lines.
Heijunka: The creation of a level schedule by sequencing orders in a repetitive pattern and smoothing the day-to-day variations in total orders to correspond to longer-term demand.
Internal Set-Up: Set-up tasks that can only be done when the machine is stopped. Examples are changing the fixture, changing the tools, or making adjustments.
Inventory: A major cost for most businesses, inventory is all raw materials, purchased parts, work-in-process components, and finished goods that are not yet sold to a customer.
Jidoka: See Autonomation.
Just-In-Time (JIT): System for producing and delivering the right items at the right time in the right amounts using minimal resources of manpower, material, and machinery. The three elements to making Just-in-Time possible are Takt time, Flow, and the Pull System.
Kaizen: Japanese for 'change for the better' or 'improvement'. A process in which each individual constantly looks for ways to do things better and eliminate waste.
Kanban: Japanese word for 'sign'. Typically a re-order card or other method of triggering the pull system based on actual usage of material. Kanbans are attached to the actual product, at the point of use. Kanbans cards have information about the parts (name, part number, quantity, source, destination, etc.) but carts, boxes, and electronic signals are also used.
Last In First Out: The result of a typical material or information flow system without FIFO, resulting in earlier orders being perpetually delayed by new orders arriving on top of them.
Lead-Time: The time it takes for a customer to receive a single product, from the time of customer order entry to delivery.
Lean Manufacturing: A business practice characterized by the endless pursuit of waste elimination. A manufacturer that is Lean uses the minimum amount of manpower, materials, money, machines, space, etc. to get the job done on time.
Lean Enterprise: A Lean Enterprise is an organization that is engaged in the endless pursuit of waste elimination. A Lean Enterprise has a culture that does not tolerate waste of any kind.
Lean Sigma: The combination of Lean and Six Sigma as a strategy that relentlessly pursues the reduction of lead-time and the elimination of variation throughout the value chain.
Load-Load: See Chaku-Chaku.
Machine Automatic Time: The time it takes for a machine to produce one unit, not including the manual time to load and unload.
Machine Cycle Time: The time it takes for a machine to produce one unit, including the manual time it takes to load and unload.
Milk Run: A routing of a supply or delivery vehicle to make multiple pickups or drop-offs at different locations.
Muda: Any activity that consumes resources but creates no value. Japanese word for waste.
Non Value-Added: Activities that may be necessary but do not add value as defined by the customer. Examples are packaging, paperwork, and inspection. Non value-added tasks can create value if their function is to identify and eliminate waste.
One Piece Flow: When parts are made one at a time and passed on to the next process without interruptions, back flows or scrap. Among the benefits of one-piece flow are: 1) the quick detection of defects to prevent a large batch of defects, 2) short lead-times of production, 3) reduced material and inventory costs, and 4) design of equipment and workstations of minimal size.
One-Touch Exchange of Dies: The reduction of die set-up activities down to a single step.
Operation: An activity or activities performed on a product by a single machine.
Operator Cycle Time: The time it takes for a worker or machine operator to complete a sequence of operations, including loading and unloading, bun not including waiting time.
Pacemaker: A device or technique used to set the pace of production and maintain takt time.
Plan-Do-Check-Act (PDCA): This is a basic principle followed for effective problem solving during kaizen.
Poka-Yoke: A mistake proofing device or procedure to prevent a defect during order taking or manufacturing.
Policy Deployment: Planning/implementation process that focuses on a few major long-term customer focused breakthrough objectives that are critical to company's long-term success. Planning process that links major objectives with specific support plans throughout the organization. Unifies and aligns resources and establishes clearly measurable targets against which progress toward the key objectives is measured on a regular basis.
Process: A series of individual operations required to create a design, completed order, part, or product.
Production Control Board: Tool used to track production at the hour level. Should include anticipated production, actual production, problems that occurred to prevent reaching the hourly goal, and corrective action taken. This shop floor visual allows anyone to walk into a department and know instantly how they are running vs. their schedule. Most importantly it tracks the downfalls, providing valuable information to support groups for corrective action.
Production Smoothing: See Heijunka.
Pull System: One of the 3 elements of JIT. A system of cascading production and delivery instructions from downstream to upstream activities in which nothing is produced by the upstream supplier until the downstream customer signals a need.
Push System: A system of production and delivery from upstream to downstream in which all activities are produced then forwarded to the next process, regardless of their needs. The opposite of pull.
Kaizen Events: The never-ending pursuit of waste elimination by creating a better workplace, better products, and greater value to stakeholders.
Sensei: A revered master or teacher
Set-Up Time: The time required to change a tool or machine over. This time starts at the last good part and ends at the first good part form the next die/tool
Six Sigma: A methodology and set of tools used to improve quality to less than 3.4 defects per million or better.
Single Minute Exchange of Dies (SMED): A series of techniques for changeovers of production machinery. Reduces the time between last good piece of one run and the first good piece of the next run.
Spaghetti Chart: A map of the path taken by a specific product as it travels down the value stream, or the path that an operator takes during standard work. So called because the path, before eliminating waste, often looks like a plate of spaghetti.
Standard Work: Standard work is the most efficient combination of member, machine, and material. The three elements of standard work are 1) takt time, 2) work sequence, and 3) standard work-in-process. Performing standard work allows for a clear and visible 'standard' operation. Deviation from standard work indicates an abnormality, which is then an opportunity for improvement.
Standard Work Combination Sheet (SWCS): A document detailing the sequence of production steps assigned to a single worker performing Standard Work. This document outlines the best combination of member and machine.
Standard Work Layout Sheet: A visual work instruction drawing for Standard Work. Shows the work sequence, takt time, standard work-in-process, and layout of the cell or workstation.
Standard Work-In-Process (SWIP): The minimum work-in-process needed to maintain standard work. SWIP parts are 1) parts completed and in the machine after auto cycle, 2) parts placed in equipment with cycle times exceeding Takt time, and 3) the parts currently being worked on or handled by the operators performing standard work.
Supermarket: A tool of the pull system that helps signal demand for the product. In a supermarket, a fixed amount of raw material, work-in-process, or finished material is kept as a buffer to schedule variability or an incapable process.
Takt Time: Takt time is the pace at which the customer is buying a particular product or service. Takt time is the total available production time divided by the total daily customer demand. Takt time is not how long it takes to perform a task. Takt time cannot be reduced or increased except by changes in production demand or available time to work. Takt time is one of the 3 elements of JIT. Takt is a German word for 'beat' or 'rhythm'.
Throughput Time: The time required for a product to proceed from concept to launch, order to delivery, from any single process to another, or raw materials into the hands of the customer.
Total Productive Maintenance (TPM): A series of methods to ensure that every machine in a production process is always able to perform its required tasks so that production is never interrupted. Maximizes equipment effectiveness and uptime throughout the entire life of the equipment.
Toyota Production System (TPS): A methodology that resulted from over 50 years of Kaizen at Toyota, one of the most successful companies in the world.
Two-Bin System: An example of both visual management and the pull system, whereby two bins or containers are used to trigger reorder of parts or materials. Each bin contains enough parts to last during the delivery lead-time. When one bin is empty, it is time to reorder the two-bin quantity.
Value-Added: work that the customer is willing to pay for. A transformation of the shape or function of the material/information in a way that the customer will pay for.
Value Stream Mapping: Creating a visual picture of the 'Current State' or how material and information flows from suppliers through manufacturing and to the customer. Total lead-time, process cycle times and value-added times are measured. The Future State is created based on goals desired based on market conditions and strategic planning.
Visual Control: The placement in plain view of all tools, parts, production activities, and indicators of production system performance, so everyone involved can understand the status of the system at a glance. Examples include color-coding, charts, andons, schedule boards, labels, and markings on the floor.
Water Strider/Shopper: A skilled and well-trained person who makes the rounds supplying parts, assisting with changeover, providing tools and materials, and any additional help needed to maintain Std. Work and keep the flow going. The member has a routine and knows all processes thoroughly enough to step in if needed.
WIP: Minimum Work-In-Process needed to maintain std. work. Parts include: 1) parts completed and in the machine after auto cycle, 2) parts placed in equipment with cycle time exceeding Takt time, and 3) parts currently being worked on or handled by the operators
Work Sequence: The defined steps and activities that need to be performed in order for the work to be completed.
Acronyms:
3P: Production Preparation Process
CA: Corrective Action
COT: Complete and On Time
CCPM: Customer Complaints Per Million
CQR: Customer Quality Report
CT: Cycle Time
FIFO: First In First Out
JIT: Just In Time
KPI: Key Performance Indicators
LIFO: Last In First Out
LTL: Load-To-Load, direct transfer of loads
MRP: Material Requirement Planning
NVA: Non-Value Added
OSHA: Occupational Safety & Health Administration
PCB: Production Control Board
PDCA: Plan, Do, Check, Act
QA: Quality Assurance
RCI: Rapid Continuous Improvement
SCAR: Supplier Corrective Action Report
SMED: Single Minute Exchange of Dies
SW: Standard Work
SWCS: Standard Work Combination Sheet
SWIP: Standard Work In Process
SWL: Standard Work Layout
SWS: Standard Work Sheet
TOF: Time Observation Form
TPM: Total Productive Maintenance
TPS: Toyota Production System
TQM: Total Quality Management
TT: Takt Time
USA: Understand, Simplify, Act
VA: Value-Added
VSM: Value Stream Map
WIP: Work In Process