In Summary: Lean Manufacturing- Principles and Tools

Lean manufacturing is a philosophy that seeks to establish reliable manufacturing activities to minimize process and production wastes. The successful implementation of Lean tools means that companies can accomplish their business goals using few resources. It is a customer-centric approach that companies use to deliver valuable products.
Lean manufacturing is instrumental in strengthening operational excellence and asset reliability across facilities. It facilitates the reduction of manufacturing wastes, simplifies routine workflows and improves the consistency of operations. It helps standardize production activities, effectively manage production, operations and maintenance inventories, develop continuous improvement measures and create a value stream for products.
In this article we summarize principles and top 20 tools of lean manufacturing.

A key tenet of lean is reducing or eliminating waste, also known as “muda.” Waste is defined as the steps or actions within a process that aren’t required to complete a process (called “non value-adding”).
These elements include:
• Defects
• Overproduction
• Waiting
• Non-utilized talent
• Transportation
• Inventory
• Motion
• Extra-processing
Learn more about The 8 Deadly Wastes

The five lean manufacturing principles are the foundation of Toyota’s success and can help businesses create products centered on what customers want. 
Identify Value
The first lean principle, identifying value, is also the first step in the journey to become lean. This step requires businesses to define what customers value and how their products or services meet those values. In this case, value requires:
* Designing products to meet the needs of customers
* Removing features that do not specifically meet those needs
By designing products to meet specific needs, businesses will eliminate wasteful steps that may have been required for unwanted features. Design for Six Sigma (DFSS) is one method that can help businesses identify value. Using DFSS, companies can systematically define, measure, and analyze what their customers want. Companies can then design products tailored for their customers.
Map the Value Steam
The second lean manufacturing principle is mapping the value stream. A value stream is the complete life-cycle of a product, which includes the product’s design, the customers’ use of the product and the disposal of the product.
This step requires companies to identify and map the product’s value stream. Lean tools like Value Stream Mapping (VSM) can be used to visually map out the entire product flow. Once the value stream is mapped, it will be easier to find and minimize steps that do not add value.
Create Flow
The third lean principle is creating flow. Efficient product flow requires items to move from production to shipping without interruption and can be achieved by strategically organizing the work floor. Every factor, from people and equipment to materials and shipping, must be taken into account to ensure products seamlessly move through the production process.
A well-organized work floor will result in reduced production time, inventory size and material handling.
Establish Pull
Closely related to creating flow, the fourth lean principle requires businesses to use a pull-based production system. Traditional production systems use a push system, which starts with purchasing supplies and proceeds by pushing material through the manufacturing process, even when there isn't an order. While push systems are easy to create, they often result in large inventories and a significant amount of work-in-progress (WIP).
A pull system, however, pulls a customer's order from the shipping department, which then prompts new items to be manufactured and signals that additional supplies need to be purchased. Lean manufacturing tools like Kanban can help businesses establish a pull system to control the flow of materials in a production system.
Using a pull system, businesses will:
* Increase output
* Maximize usable workspace
* Reduce inventories
*Eliminate overproduction and underproduction
*Eliminate errors caused by having too much WIP
Seek Perfection
The final lean manufacturing principle requires companies to seek perfection. While seeking perfection may seem straightforward, it is often one of the most difficult principles to successfully apply in the workplace. Seeking perfection requires companies to continuously improve their practices and often requires a shift in the workplace culture.

There are many different lean manufacturing tools that you can implement within your business. Together they form one comprehensive whole that can be implemented as Lean within your company. These tools are most effective if they are implemented together, however many can be used on their own to solve specific issues within your business.

The 5S Method refers to five Japanese and English terms that begin with an “S” and provide a workplace organization method.
What does each “S” stand for?
* Sort (Seiri): Decide which items in a factory are necessary and which ones are not. Get rid of the ones that are not.
* Straighten (Seiton): Make sure every item in a factory is in the right place. Items should be easy to find and access.
* Shine (Seiso): Clean factory regularly. By getting rid of dirt, garbage, etc. you can more easily identify problems in the manufacturing process.
* Standardize (seiketsu): Create standards to ensure a clean and neat factory floor.
* Sustain (shitsuke): Create habits that ensure standards are met over the long term. Set responsibilities for managers and operators to ensure that habits are set.  
Learn more about A PRACTICAL APPROACH TO THE SUCCESSFUL PRACTICE OF 5S

Andon is a visual feedback system for the plant floor that indicates production status, alerts when assistance is needed, and empowers operators to stop the production process.
How does Andon help?
Andon acts as a real-time communication tool for the plant floor that brings immediate attention to problems as they occur – so they can be instantly addressed.

How many times have your projects gotten stuck somewhere between development and delivery? Bottleneck analysis is a structured way of looking at the processes and workflows for developing a product or service. Bottleneck analysis is also used to address both present and future issues, by identifying and addressing operational and process challenges.
Applications:
Utilizing Lean practices to spot and rectify a bottleneck saves companies time, energy and money. Depending on the type of bottleneck, there are several things you can do to address it. For example, bottlenecks caused by inefficient processes can be fixed through streamlining and improving those processes; if it is instead caused by a lack of resources, you may need to hire more people or purchase technology to make your existing resources go further.
Also read about The Theory of Constraints (TOC)

Continuous Flow is the opposite of batch production and is closely associated with Kanban and Just-in-Time. The goal of Continuous Flow is to use ongoing examination and improvement to integrate all elements of production. By aiming for a Continuous Flow production process, waste and other problems come to the surface and can then be solved. Ultimately, many lean principles and tools center around creating a Continuous Flow production process.
The Continuous Flow process generally involves a factory running 24/7 without interruption and with little waste. Areas like oil refining, metal smelting, and natural gas processing are ideal for the Continuous Flow process.  
What are the benefits of Continuous Flow?
The benefits of Continuous Flow include:
* Stability.
* Continuity.
* Waste-less process.
* No time wasted.

Heijunka is a form of production scheduling that purposely manufactures in much smaller batches by sequencing (mixing) product variants within the same process.
How does Heijunka help?
Heijunka reduces lead times (since each product or variant is manufactured more frequently) and inventory (since batches are smaller).
There are two ways of leveling production using the Heijunka concept: leveling by volume and leveling by type. Leveling by volume deals with the number of items per type of product produced in each batch. It helps to see what products should be prioritized according to customer demand. Leveling by type adds different sequences of what product is being produced in every batch. It maintains the needed variety of products to be produced on a weekly or monthly basis

Hoshin Kanri is a seven-step planning process that involves a systematic method to meet strategic planning goals and manage progress towards those goals.

What is the goal of Hoshin Kanri? 
The goal of Hoshin Kanri is to determine your strategic objectives and then align them with specific resources and action plans to meet those objectives.
The 7-steps of Hoshin Kanri:
- Determine an organizational vision. Figure out what your current mission and long-term vision is.
- Establish breakthrough objectives. Determine what significant improvements a business needs in the next three to five years.
- Come up with annual objectives to complete on a yearly basis.
- Determine metrics to measure objectives.
- Implement objectives.
- Review objectives monthly. Determine your progress each month to see where your business needs improvement.
- Review objectives yearly. Determine your progress each year to see where your business needs improvement.

Learn more about The 7 Steps of Hoshin Kanri Planning (TOC)

Jidoka is the idea that manufacturers should design equipment to partially automate the manufacturing process (partial automation is typically much less expensive than full automation) and to automatically stop when defects are detected.
How does Jidoka help?
After Jidoka, workers can frequently monitor multiple stations (reducing labor costs) and many quality issues can be detected immediately (improving quality).
Learn more about What is Jidoka

Just-in-time manufacturing is an on-demand system that allows manufacturers to go into production only after the customer has requested a product. This means that companies do not have to stock up on unnecessary inventory, lowering the risk of some components or products being overstocked or damaged while being stored.
Applications:
Professionals who use Lean principles should consider JIT if their business is capable of working on-demand and can minimize the risk of only carrying inventory as needed. JIT can be an effective framework for managing inventory, but it can also make it more difficult to meet customer demand if there is a breakdown in the supply chain.
As an example, the self-publishing sector often uses this model, only printing books as they are ordered. Digital distribution for media products has also helped to minimize the costs associated with excess materials.
Organizations in sectors like manufacturing should carefully evaluate their supply chains and minimize the potential for disruption when implementing JIT. If a critical supplier has to suspend operations, for example, it’s important to have a backup plan to ensure that the final product can still be developed.
Learn more about JIT (Just in Time) Production System

Kaizen is the Japanese word for “continual improvement.” The term refers to activities that improve every function of a business and is generally applied to manufacturing, but can be used to make almost any business more efficient.
By definition, Kaizen includes the involvement of all employees, from upper management to assembly line workers and can be used to improve every process in a supply chain, from purchasing to logistics. The lean manufacturing tool was first used by the Japanese in World War Two and was a major influence of the book “The Toyota Way.”
What is the goal of Kaizen?
Kaizen seeks to improve standardized processes in order to eliminate waste, fix workflow issues, and solve business problems.      
How is Kaizen implemented? 
The Kaizen method generally involves 5 primary steps:
- Identify problem area that will be given focus.
- Utilize videotape to analyze current method.
- Test and evaluate improvement tactics.
- Implement improvements.
- Analyze results and present to upper management for feedback.
What is Kaizen most applicable to?
The Automotive industry. In fact, the Toyota Production System made the tool famous. If problems occur within the production process, Toyota assembly line personnel and their supervisors are expected to stop the production process and begin a Kaizen.

Overall equipment effectiveness (or OEE) measures how much planned productive time is actually productive. For example, imagine you’re planning to work on a project for an hour, but then spending 20 minutes of that time answering a client call, meaning your OEE would be about 67% (40 minutes of actual production time, divided by 60 minutes of planned production time).
In terms of manufacturing, OEE takes into account the percentage of “good parts” produced (“good parts” being the parts that meet the quality standards of that particular company). In the example above, if your project has parts that are poorly constructed, those would not count towards the “good parts” or overall OEE score.
According to oee.com, overall equipment effectiveness can be calculated by multiplying the following three factors:
* Availability
* Performance
* Quality
These three factors are defined as follows:
- Availability = Run Time Divided by Total Planned Production Time
- Performance = (Ideal Cycle Time Multiplied by Total Count) Divided By Run Time
- Quality = Good Count Divided by Total Count

Applications:
Companies apply OEE in order to increase production effectiveness and perform effectively and efficiently by establishing accurate baselines of performance—while still maintaining quality standards. This efficiency saves companies money and time.
Learn more about Overall Equipment Effectiveness (OEE) Calculations, Example

Poke Yoke was developed by Toyota and is very similar to Jidoka. The idea of Poka Yoke is to prevent mistakes from becoming defects. Mistakes, it argues, are inevitable, but defects that actually reach customers are preventable. The goal is to create a form of quality control that highlights defects automatically and eventually takes humans out of the equation.
Why use Poka Yoke?
The tool was invented because of human error. Humans that perform repetitive manufacturing tasks day in and day out can very easily miss common mistakes and defects. Automation was necessary to improve the manufacturing process.
A real-life example of Poka Yoke:
An alarm that goes off automatically when you leave a car without turning off the headlights. Another example is a conveyer belt that rejects a product that is underweight. The goal is to prevent mistakes automatically, without human inspection.
Learn more about Poka-Yoke Technique

Single-Minute Exchange of Die reduces setup (changeover) time to less than 10 minutes. SMED 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
How does Single-Minute Exchange of Die help:
SMED enables manufacturing in smaller lots, reduces inventory, and improves customer responsiveness.

Standardized Work is a tool used to document current best practices, improve the standard, and ensure that the new standard becomes a baseline for improvement.
What does Standardized Work improve?
Standardized Work improves 3 important aspects of the manufacturing process:
* The rate at which products are produced in order to meet customer demand.
* The operator’s work sequence to produce products at that time rate.
* The standard inventory needed to ensure a smooth manufacturing process.
The main benefits of Standardized Work include:
* Better documentation of current processes.
* Easier training for operators.
* Few injuries and strains.
* Baseline to make improvements.
* Reduces variability.
* Adds discipline to a work culture.
* Promotes problem solving.
* Increases teamwork across organization.

Takt Time is the pace of production (e.g., manufacturing one piece every 34 seconds) that aligns production with customer demand. Calculated as Planned Production Time / Customer Demand.
How does Takt Time help?
Takt Time provides a simple, consistent, and intuitive method of pacing production. It’s easily extended to provide an efficiency goal for the plant floor (Actual Pieces / Target Pieces).

Learn more about What Is Takt Time and The 10 Most used time terms in manufacturing and service

Total Productive Maintenance (TPM) is the machinery equivalent of Total Quality Management (TQM) and involves everyone in the organization in focusing on eliminating the six big losses through the use of a performance measure known as OEE. TPM builds on Preventive maintenance and predictive maintenance programs and involves the operators through autonomous maintenance. This is another foundation stone of Lean manufacturing which ensures that you not only have reliable processes by eliminating breakdowns but also standardizes your processes, reduces and improves setups and increases product quality.

Value stream mapping is a technique developed from Lean manufacturing. Organizations use it to create a visual guide of all the components necessary to deliver a product or service with the goal of analyzing and optimizing the entire process.
Value stream mapping is used in a variety of industries, including manufacturing, finance and healthcare. This principle takes all the people, processes, information and inventory necessary, and displays them in a flow chart in order to get an overview of the business.
Applications:
Value stream mapping can be applied to your organization by methods such as:
* Encouraging continuous improvement in processes
* Enabling culture change within an organization
* Facilitating clear collaboration and communication


Learn more about How to Create a Value Stream Map

Visual Management is a communication technique that uses visual aids to convey messages quicker and more efficiently
The objectives of Visual Management are:
* Clarify waste.
* Display problems in a simpler way.
* Clearly indicate your efficiency goals.
* Increase effective communication.
An example of Visual Management
 Stock controls, auditing boards, and shadow boards. Often times, visual management can improve communication and help improve efficiency. Other times, visual aids can become confusing and too much to remember.  
Where is Visual Management best applied
Work instructions can often be simplified and far easier to understand when visual aids are included. For example, if a work must build a piece of furniture from multiple parts, it will often be better understood in a visual format. It is particularly useful for tasks that are difficult to explain with words alone. Another example may be showing works a picture of a completed task.

May be loosely interpreted as autonomous defects control. It supports Just in Time (JIT) by never allowing defective units from a preceding process to flow into and disrupt a subsequent process.

The goal of In Station Process Control (ISPC) is to produce quality products in-station and eliminate waste, by preventing defects from being produced and passed downstream through the use of standardized tools and procedures.

ISPC enables the Work Groups and Work Groups members to:

Understand and acknowledge their customer’s needs and expectations
Participate in the development of new processes by identifying control plans, reaction plans, and control methods
Provide input and use personal experience to improve current manufacturing processes
Create and enforce the standard methods used to perform their work
Manage their work area
Identify opportunities to eliminate waste
Improve quality
Solve their manufacturing problems at their level, and control their processes
Use of ISPC ensures that the Work Group can control the quality, manufacturing time, material flow, and cost of their products.

Kanban is a visual method for controlling production as part of Just in Time (JIT) and Lean Manufacturing. As part of a pull system it controls what is produced, in what quantity, and when. Its purpose is to ensure that you only produce what the customer is asking for and nothing more. It is a system of signals that is used through the value stream to pull product from customer demand back to raw materials.

Its literal meaning is that of a flag or sign, when you see that flag you know that it is time to manufacture the next part. Kanbans can take many forms but in most production facilities they will use Kanban cards or bins to control the process, although there are no limits to how you can control and design kanbans; only your imagination.

Learn more about Kanban System

In Japanese, Gemba means “the real place.” In business, refers to an area where there is value created. In manufacturing, it refers to the factory floor. It can also be a construction site, sales floor, etc. The idea of Gemba in lean manufacturing is that management must go to factory floor to search and fix visible problems. Manufacturing problems, Gemba argues, cannot be solved from an office. They require an actual physical presence by problem solvers on the manufacturing floor.

Gemba is a step by step process:
* Engineers physically go to manufacturing floor to observe processes.
* Engineers collect data and understand the work being done
* Engineers ask questions.
Engineers learn about problems and come up with solutions.  
Gemba Walks refer staff taking the time to walk through the factory, examine what is going on, and determine if there are any issues. In the lean management philosophy, staff are expected to do Gemba Walks at least once a week.