Lean Manufacturing and Environment
Lean and Environment Toolkit
Chapter 5: 6S (5S + Safety)
- Introduction to 6S
- How to Identify EHS Issues during “Sort”
- How to Incorporate EHS into 6S Inspections
This chapter focuses on making improvements to work areas using 6S, a variation of the 5S method. 6S can be a powerful way to reduce risks, improve waste management, and ensure that your facility is a safe and healthy place to work.
6S is a method used to create and maintain a clean, orderly, and safe work environment. 6S is based upon the five pillars (5S) of the visual workplace in the Toyota Production System, plus a separate pillar for safety. 6S is often the first method companies implement in their Lean journey, since it serves as the foundation of future continual improvement efforts. More detailed information on 6S can be found in Appendix A.
6S consists of six pillars:
The six pillars work together to support improvement efforts at your company. They help increase productivity, reduce defects, make accidents less likely, and reduce costs. 6S also fosters a culture of continual improvement and employee engagement that is essential for successful implementation of Lean. 6S often makes it easier to implement other Lean methods such as cellular manufacturing, one-piece flow, and just-in-time production.
CASE STUDY: ROBINS AIR FORCE BASE
Robins Air Force Base houses the Warner Robins Air Logistics Center, a major depot for repairing aircraft and producing spare parts for the U.S. Air Force. The Base implemented point of use cabinet systems through kaizen events, 6S, and visual controls to reduce the time and distance that workers travel to retrieve hazardous materials and the amount of waste generated. Value stream mapping and 6S were used to set up a system for collecting and transporting hazardous wastes, which eliminated process steps, saved time handling wastes, and reduced how often waste drums were handled. Robins AFB reorganized its hazardous waste management facility using 6S and visual controls to enhance the monitoring of waste management processes and decrease the chance of accidents and spills. The C-130 Aircraft Paint Shop used 6S to improve its paint system, which increased productivity, improved worker safety, and decreased volatile organic compound emissions, chemical use, and storage space.
Figure 11: The Six Pillars of 6S
Environmental wastes can be a symptom of a suboptimal system. 6S can help your company reduce waste and improve environmental performance leading to increased system productivity. You also can use 6S to minimize risks to the health of workers and the environment. Full implementation of 6S requires looking not only at the quantity, usefulness, and frequency with which an item is used in a work area, but also the risk or toxicity of the item. It also means paying close attention to what ends up in waste streams and how to manage those wastes.
Expanding the scope of 6S to include EHS concerns can help your company to:
- Name at least three ways your company could use 6S to improve its environmental performance and reduce wastes.
- What metrics could you use to track environmental, health, and safety improvements from 6S activities?
- What ideas do you have for improving your work area?
- Reduce the chance that paint, solvent, or other chemicals expire or become off-specification before they can be used and then require disposal;
- Save floor space, which makes it possible to save energy costs by consolidating operations and closing unneeded storage areas;
- Avoid productivity losses from injuries and occupational health hazards by providing clean and accident-free work areas; and
- Prevent environmental and occupational health and safety compliance issues by preventing or quickly correcting any spill or leaks.
EHS issues are relevant to all six pillars of 6S. As a starting point, this toolkit describes how to:
- Distinguish between hazardous and nonhazardous items in your work area during Sort—an initial step in 6S. Use yellow tags or other visual cues in red-tagging to identify EHS issues, harmful materials, and environmental wastes.
- Incorporate questions about EHS issues into the inspection and evaluation activities that occur in the Shine and Sustain pillars. Inspect work areas in plant-wide and area-specific 6S inspections and audits to make sure that EHS concerns are managed properly.
|6S Implementation Tips|
Some additional ideas on how to incorporate EHS concerns into the 6S process are given in the box below.
The objective of Sort is to identify items that are not needed in a work area and to get rid of them. This is done through a process called red-tagging. During a red-tagging project, you can examine your work area to identify any environmental, health, and safety issues at the same time, using yellow tags or other visual cues.
A yellow-tag strategy is a simple method of identifying environmental wastes and items that may be harmful to human health or the environment in the work area, evaluating the need for these items and potential alternatives, and addressing them appropriately. A yellow-tag strategy is designed to supplement a red-tag strategy. Yellow tags highlight EHS hazards or improvement opportunities.
The basic steps in yellow-tagging are the same as in red-tagging, so you can implement them together or separately. The process can be divided into four steps.
At the start of a yellow-tagging project, your team should identify two types of targets: (a) the physical areas where tagging will take place; and (b) the specific types of items you will evaluate. Involve EHS personnel in your yellow-tagging team to help you find additional wastes and opportunities for improvement.
Potential items to consider in yellow-tagging include:
- EHS hazards in the workplace;
- Chemicals and other hazardous materials; and
- Environmental wastes.
After choosing targets, your team should agree on criteria for evaluating yellow-tagged items. You can continue to use red-tagging and your company’s red-tag criteria to determine whether an item is needed in the work area based on its usefulness for the work at hand, the frequency with which it is used, and the quantity that is needed. For yellow tags, you may want to use criteria related to the risk of an item, the availability of alternative materials or equipment, or to an opportunity for improved environmental performance.
Yellow tags can serve as warning tags that alert workers about existing or potential hazards in the work area or that identify potential areas to target for improvement in the future. For example, a yellow tag on a chemical could cause you to ask whether a less toxic material could be used for the same purpose. Similarly, a yellow tag on an item in a red-tag holding area could indicate that the item needs to be treated differently for disposal or reuse because of its risk.
Yellow tags could be as simple as yellow sticky notes stating the reason for the yellow tag, or they could also contain standard data that will allow your company to evaluate performance improvements from 6S and that will support your company’s overall materials tracking system. An example yellow tag is below.
It is best to attach yellow tags to items during a short, focused event, to get a snapshot of the current state of the work area. Unless there is an immediate danger to people’s safety, do not spend time at this stage correcting issues or evaluating what to do with items. Instead, use the yellow tags to highlight potential EHS issues or opportunities in the target work area.
The next step involves applying the criteria from Step 1 to determine what to do with yellow-tagged items.
|Asking Why Five Times (2)|
The final step in a yellow-tag strategy is to document necessary information from the yellow-tagging process in a log book or other tracking system your company uses. This should be done at the same time as you record data from red tags, ideally as part of the same system. This will allow you to track the improvements and savings that have resulted from your yellow-tagging efforts.
As with any Lean project, it is important to share your results with others, celebrate your success, and identify any follow-up items. Posting the results of yellow-tagging projects on activity boards can show others at your company what you have been able to achieve and can generate ideas for further improvement.
Most companies who implement 6S seek to sustain the improvements made during initial 6S events. Shine activities often include daily cleaning and inspection by workers in their work area. Sustain activities often include weekly or other periodic audits to assess progress with 6S implementation.
Remember that what gets measured gets managed. By explicitly incorporating EHS items into 6S inspections and audits, you can eliminate more waste and risk from each work area. 6S inspections and audits can also reinforce workers’ awareness of important tasks and issues that affect worker health and safety and environmental performance. For companies implementing an environmental management system (such as an ISO 14001-type EMS), 6S inspections and audits create valuable opportunities to regularly ensure that EHS procedures are followed on the shop floor.
Inspection checklists and audit questions are powerful tools to sustain 6S improvements and to prompt the identification of new improvement opportunities.
The list of 6S Inspection and Audit Questions on page 56 contains questions used by some companies to ensure that environmental wastes and risk are routinely identified, properly managed, and eliminated where possible.
These questions can be adapted to work in a variety of 6S implementation assessment tools, particularly where a common system is used to assess 6S implementation across many work areas. Your company may use a simplified rating system to assess 6S implementation progress, such as a 0–5 rating for each 6S pillar. In this case, these questions can be used to train 6S inspectors and auditors, or to provide background information for a broader rating category or question that focuses on overall efforts to address EHS issues and opportunities in a work area.
Some organizations have developed detailed audit checklists that include, or focus exclusively on, environmental and safety issues. Appendix E includes a sample 6S Audit Checklist that was developed by a company to focus on safety issues.
When developing Shine cleaning and inspection checklists for a work area, it will often be useful to develop additional questions that are tailored to address specific materials, equipment, and/or work practices in that work area. EHS personnel can help to develop specific checklist items and questions that can integrate EHS management procedures and waste identification opportunities into Shine inspections for pollution control equipment, hazardous chemicals, and other aspects of a work area that could pose health or safety hazards to workers.
|6S Inspection and Audit Questions for Eliminating Environmental Waste and Risk|
Sort (Get rid of it)
Set in Order (Organize)
Shine (Clean and solve)
Safety (Respect workplace and employee)
Standardize (Make consistent)
Sustain (Keep it up)
6S is modeled after the 5S system designed to reduce waste and optimize productivity through maintaining a clean, orderly workplace and using visual cues to achieve more consistent operational results. 6S uses the 5S pillars with an additional pillar for safety. The six pillars of 6S are:
- Sort (Get rid of it);
- Set in order (Organize);
- Shine (Clean and solve);
- Safety (Respect workplace and employee);
- Standardize (Make consistent); and
- Sustain (Keep it up).
The pillars work together to increase productivity, reduce defects, make accidents less likely, save time, and reduce costs. When expanded to include EHS issues, they can also help reduce hazards and improve environmental performance.
The following four steps provide an example of how EHS issues can be identified and addressed through 6S using yellow tags along with red tags in the Sort process. The objective of this strategy is to identify environmental wastes in the work area with a yellow tag, evaluate their need and potential alternatives, and address them accordingly.
- Identify yellow-tag targets such as EHS hazards, chemicals and other hazardous materials, and environmental wastes. Also, agree on criteria for evaluating yellow-tagged items.
- Make and attach yellow tags to identified items and include data to allow for evaluation of performance improvements.
- Evaluate and address yellow-tagged items.
- Document results.
By explicitly incorporating EHS issues into all six pillars during 6S inspections, you can eliminate more waste and risk. Inspection checklists and audit questions are powerful tools to sustain 6S improvements and to prompt identification of new improvement opportunities.
(2) Based on an example from Robert B. Pojasek, “Asking ‘Why?’ Five Times,” Environmental Quality Management (Autumn 2000): 83.