The Six Big Losses in Lean Manufacturing: A Concept

The Six Big Losses in lean manufacturing is a concept and practice that is used to categorize equipment-based losses and maximize overall equipment effectiveness. In essence, it aims to reduce waste and bring more value to the end customer. Japanese entrepreneur, Seiichi Nakajima, developed the Six Big Losses in 1971 while at the Japanese Institute of Plant Maintenance. Today, these core objectives are still some of the best foundational guiding principles of lean manufacturing.

What are the Six Big Losses?

The Six Big Losses in lean manufacturing directly aligns with Overall Equipment Effectiveness (OEE). Moreover, it provides an added actionable level of detail about OEE losses. The Six Big Losses can be split into three general categories:

  1. 1. Availability Losses
  2. 2. Performance Losses, and
  3. 3. Quality Losses

Traditionally, the Six Big Losses in Lean Manufacturing were:

  1. 1. Equipment Failure 
  2. 2. Setup Adjustments
  3. 3. Idling and Minor Stops
  4. 4. Reduced Speed
  5. 5. Process Defects, and
  6. 6. Reduced Yield

However, we recommend you use a simpler and more consistent set of names to adopt this practice into your organization:

  1. 1. Unplanned Stops
  2. 2. Planned Stops
  3. 3. Small Stops
  4. 4. Slow Cycles
  5. 5. Production Rejects, and
  6. 6. Startup Rejects

By addressing the Six Big Losses in lean manufacturing, it will directly lead to a reduction in availability, performance, and quality losses. As a result, your OEE score will improve, meaning your manufacturing processes will be more efficient. 

Table depicting what the six big losses in lean manufacturing were traditionally called vs what they're update to
1. Unplanned Stops

Unplanned stops happen when equipment is supposed to be working, but is not because of an unplanned event. For example, equipment breakdown, tool failure, unplanned maintenance, a broken part, or lack of operators. 

2. Planned Stops

Planned stops happen when equipment is supposed to be working, but is not because a planned event. For example, changeovers, planned cleaning, tooling adjustments, quality inspections, scheduled maintenance, etc. Additionally, it is important to note that companies also often categorize breaks and meetings as planned stops.

3. Small Stops

Small stops happen when equipment stops for a brief moment (typically one or two minutes), but is immediately resolved by an operator. Essentially, this type of loss includes stops that happen well under five minutes and do not require the help of a maintenance worker. Small stops occur often and this is because of common events. For example, misfeeds, material jams, equipment issues, blocked sensors, and periodic quick cleanings.

4. Slow Cycles

Slow cycles happen when equipment runs slower than the Ideal Cycle Time, which is theoretically the fastest possible time to manufacture one piece. Common reasons for slow cycles include poor lubrication, substandard material, dirty or worn out equipment, startup or shutdown, and an inexperienced operator.

5. Production Rejects

Production rejects include defective parts that are created during production. Common reasons for production rejects include operation/equipment handling errors, incorrect equipment settings, and lot expiration.

6. Startup Rejects

Startup rejects are defective parts that are produced during the start of production or after changeovers (the time it takes to get a production line or machine running to work on new product). Furthermore, startup rejects are often thrown away or reworked into new parts. Common reasons for startup rejects include poor changeovers, incorrect settings, and equipment wear.

Benefits of Putting the Six Big Losses into Practice

Improved Information

In the short run, the Six Big Losses in lean manufacturing provides companies with additional information that aligns with and extends OEE. 

Improved Actions

In the long run, the Six Big Losses in lean manufacturing makes it easier for companies to recognize effective countermeasures for equipment-based losses and take action to improve their processes.

Reducing the Six Big Losses in Lean Manufacturing with TheLeanSuite

Today’s workforce is constantly evolving. That is to say, employees need continuous learning and performance support to do their job well. But, there’s no need to worry — improve the performance of your frontline workers and reduce the Six Big Losses in lean manufacturing with our connected worker platform. TheLeanSuite offers a variety of different solutions to help you ultimately accelerate your continuous improvement program:

Suggestion Platform

Collect suggestions and ideas on improvement opportunities for your shop-floor to minimize some, if not all, of the Six Big Losses in lean manufacturing.                 

Issue Tracker

Use the Issue Tracker to tag and quickly close critical problems on your shop-floor, helping you to minimize the Six Big Losses in lean manufacturing as much as possible.  

Continuous Improvement System

Open a quick or complex Kaizen so that you can  simplify, standardize, and spread your best practices to mitigate some, if not all, of the Six Big Losses in lean manufacturing as much as possible.