Lean Manufacturing Tools and How (and When) to Use Them

Before you can know the tools, you have to understand the concept: What is lean manufacturing?

The idea of lean manufacturing originally began as early as the 1930s with what is now known as the Toyota Production System (TPS) or Toyota Way of manufacturing in Japan. The main goal was to use smaller factories with specified goals to minimize inventory levels and the waste of natural resources. By the 1980s, this had evolved in America enough for John Krafcik to publish an article on the values of “Lean” production systems.

The modern definition from James P. Womack and Daniel T. Jones in the 1990s identified five key principles:

Precisely specify value by specific product, identify the value stream for each product, make value flow without interruptions, let customer pull value from the producer, and pursue perfection. “Lean Thinking: Banish Waste and Create Wealth in Your Corporation” - Womack & Jones

Sometimes known interchangeably as just-in-time (JIT) manufacturing, the key to lean production is to increase quality and productivity while minimizing waste. In order to achieve this, many producers have turned to lean manufacturing tools. Here’s what you need to know:

What are Lean Tools in Manufacturing?

Lean manufacturing tools include anything meant to reduce waste or increase productivity during production. This can include physical equipment, software programs, production processes, or employee training methodologies. Some are self-explanatory based on their names, incredibly easy to implement in any business setting. Others are highly detailed and well-documented concepts which have been tested and perfected in factories all over the world.

Important Reminder: Some of these tools have very specific applications while others are far more conceptual in their execution. These definitions are intended as generalizations of the overall idea, benefit, or goal each tool offers.

Some well-known lean manufacturing tools include:

• 5S (Five S): Sort (Seiri), Straighten/Order (Seiton), Shine (Seiso), Standardize (Seiketsu), and Sustain (Shitsuke)
• Continuous Flow or Kaizen
• Error Proofing or “Poka-Yoke”
• Just-In-Time (JIT)
• Kanban Boards
• Lean Six Sigma
• Single-Minute Exchange of Die (SMED)
• Total Productive Maintenance (TPM)

The exact tools necessary for your work depends on a variety of factors. Of course, these tools can frequently be combined to create a fully custom approach to lean manufacturing.

What are the Top 5 Lean Manufacturing Tools?

While there are many dozens (if not hundreds) of lean manufacturing tools out there, 5 in particular have become prominent for their ability to consistently reduce waste in a variety of industries:

Kaizen

The concept of kaizen is loosely translated as continuous improvement. This is achieved by following several steps in order to identify problems, review possible solutions, test improvement methods, implement those changes, then analyze the results. There is no formal end to this process, so new solutions are always being sought and tested for viability.

Kanban

If you’ve ever heard of a Kanban board, you’re likely familiar with some aspects of this lean manufacturing tool: a pull system which coordinates between your factory and customers in order to streamline product replenishment. Real-time visuals ensure everyone knows what needs to be done to meet customer demand.

Jidoka

Jidoka is the focus on automation in your manufacturing processes. The goal is to identify any area which can be automated without sacrificing quality. Jidoka tools can significantly reduce labor costs as equipment takes over previously manual tasks which simply require minimal supervision.

Value Stream Mapping (VSM)

This methodology creates a visualization of current and forecasted production flow. A literal flow chart is used to show important details on production logistics, such as real-time inventory numbers, production time, and labor levels per shift.

Total Quality Management (TQM)

As the name suggests, Total Quality Management is all about ensuring quality coming from every department involved in production. TQM seeks improvement at every level of an organization. This is often paired with Total Productive Maintenance (TPM) to focus on the equipment being used in the production.

Rounding out the top 15 tools are:

Tool	Definition
Andon	A visualization of production status which includes a fail-safe for operators to instantly stop production
Error Proofing	Known as poka-yoke in Japanese, this is the concept of preventing mistakes and achieving no defects during production
Gemba	Focuses on getting management away from the office and other distractions to be in “The Real Place”, aka the shop or factory floor where they can observe how the real work is happening
Heijunka	This Level Scheduling minimizes lead times and inventory by producing smaller batches with product variants
Hoshin Kanri	Also known as Policy Deployment, this tool is based on a company structure, starting with Strategy from the top, to the Tactics of middle management, ending with the actual Action on the shop floor
Overall Equipment Effectiveness (OEE)	A way to measure waste attributed to equipment based on availability, performance, and quality
PDCA (Plan-Do-Check-Act)	An established order for testing new improvements, also called a PDCA cycle
Single-Minute Exchange of Die (SMED)	Minimizing setup or changeover between tasks to under 10 minutes
SMART Goals	Any goals which are Specific, Measurable, Attainable, Relevant, and Time-Specific
Takt Time	A carefully calculated cycle time based on production time and customer demand

This is just a sampling of some of the most well-known and widely implemented methods of achieving lean manufacturing. Many can be combined to create customized systems to best serve your manufacturing needs.

Tool Techniques and How to Use Them

The right tool techniques can improve your lean manufacturing process. However, all lean manufacturing tools are aimed at getting to the root cause of waste. Did you know there are different types of production waste? The main three, translated from Japanese, are:

• Muda: Waste from the production process
• Mura: Waste from new or changing demand
• Muri: Waste from overburden or lost motivation

The concept of Muda can be further broken down into the 7 wastes of business process:

• Motion: Are employees or equipment being moved around the shop floor unnecessarily?
• Waiting: Are there periods of downtime between tasks which could be productive?
• Overproduction: Are you creating excess with large batch sizes without considering customer demand?
• Overprocessing: Do your products include unnecessary extras which increase production time but not value?
• Inventory: Are you holding on to too much inventory, thereby taking up space and other resources?
• Defects: Are too many low-quality products making it to customers?
• Transportation: Are you moving resources too far between different locations?

What sort of waste your business generates will determine which tools you need the most. You’ll need different tools to address the common issues and pain points associated with each type.

You might notice a lot of overlap between the various lean manufacturing tools described above. For example, bottleneck analysis is sometimes treated as an independent tool. Yet identifying a bottleneck scenario which slows down production can be done with continuous flow or error proofing tools. The definitions for JIT and Kanban are often used interchangeably. How you use or interpret a specific lean manufacturing tool is entirely up to you.

Finally, it’s important to remember no single tool is infallible. Poka-yoke, despite being a methodology based entirely around preventing errors, cannot stop genuine mistakes from happening in some capacity. In manufacturing, accidents can always happen. This is why utilizing multiple tools can provide ways to mitigate damage from unanticipated issues or human error.

5 Principles of Lean Manufacturing

Knowing the 5 principles of lean manufacturing will help you when considering various tool applications and implementation. Established in “The Machine that Changed the World” by Womack and Jones, the 5 principles are:

1. Value: Precisely identify the value of each product
2. Value stream: Map the entire value stream
3. Flow: Minimize interruptions to optimize the value stream’s flow
4. Pull: Allow the customer to pull value of products, i.e. determine what they want
5. Perfection: Aim for perfection in production

Continuous improvement, along with being the tool kaizen, is another key goal of lean manufacturing, as there will always be processes and methods which can be improved through one means or another. Whatever tools you use should address these principles in some way.

Benefits of Using Lean Manufacturing Tools

While the reduction of waste is the number one goal of lean manufacturing, there are other advantages to utilizing a lean system:

• Increase productivity
• Deliver better quality
• Lower operating costs

Utilizing lean manufacturing tools in your production process can lead to a lot of secondary benefits as well. For example, tools which increase productivity can also improve lead time reduction by waiting to know what orders are guaranteed instead of trying to forecast customer demand.

As mentioned previously, the exact tools you need largely depend on what you produce and your anticipated customer demand. If you build chairs, it may be more effective to assemble cushions in batches than it is to use continuous flow to complete one chair at a time. Yet this method, if unchecked, can lead to overproducing chair legs when demand goes down. Your lean manufacturing tools need to be specific to what works best for your business.

Pain Points of Lean Manufacturing Tools

As with all production methods, there can be drawbacks to the many lean manufacturing tools out there. For example, SMED is aimed at getting changeovers down to 10 minutes maximum. While this undeniably increases production speed, it can place a lot of pressure on the human workers responsible for completing 10 separate steps within one minute each. Fortunately, with so many lean manufacturing tools available, it’s simply a matter of problem solving to find the right one (or more) to fit your workflow.