Lean Management: Lean Tools
Lean Tools
Poka-Yoke (Error Proofing)
Poka-yoke is a Japanese term that means ―to avoid inadvertent errors.‖ A poka-yoke device is one that prevents
incorrect parts from being
made or assembled, or identifies a flaw or error. Often referred to as error-proofing, poka-yoke is actually
the first step in error-proofing a system. Error-proofing is a manufacturing technique of preventing errors by
designing the manufacturing process, equipment, and tools so that an operation literally cannot be performed
incorrectly (Munro, Ramu, & Zrymiak, 2015, p. 8). Among other things, it is a technique used to display
information that can be quickly understood by everyone.
Error-proofing is the practice of striving for zero defects using techniques, standards, and device that prevent errors from being made. Examples of preventative measures include:
- Childproof caps on prescription medicine bottles
- Different size fuel dispensing nozzles to prevent cross-fueling
- Design of parts so that they cannot be exchanged by mistake
- Color-coded parts
Error-proofing also uses shutdowns, controls, or warnings to detect errors and stop them before they become defects. Examples of detection measures include:
- Automatic shutoff on coffee pots and other small appliances
- Smoke and carbon monoxide detectors
- Warning buzzer when blood pressure drops below acceptable levels during surgery
The key to effective error-proofing is determining when and where defect-causing conditions arise, then figuring out how to detect or prevent these conditions every time. (Munro, Ramu, & Zrymiak, 2015, p. 8)
Kanban
Kanban means "visual board" in Japanese and in this context is a Japanese manufacturing system that uses instruction cards to track production. Review this approximately 10 minute read by Kanbanize, "Kanban Explained for Beginners".
Kaizen and Kaizen Blitz
Kaizen is a Sino-Japanese word for "improvement" and in this context is a concept referring to business activities that continuously improve all functions and involve all employees from the CEO to the assembly line workers. There are five fundamental principles:
- Know your Customer - Create customer value. Identify customer interests so you can enhance their experience
- Let it Flow - Target zero waste. Every one in your organization should aim to create value and eliminate waste.
- Go to Gemba - Follow the action. Value is created where things actually happen--go there.
- Empower People - Organize your teams. Set the same goals for your teams, and provide a system and tools to reach them.
- Be Transparent - Speak with real data. Performance and improvements should be tangible and visible (Kaizen Institute, n.d.)
"Blitz" means lightening fast. Kaizen blitz is a method to attack one problem and to do it quickly. It is also sometimes called a Kaizen event.
Kaizen often follows a path such as below:
5S
The 5S structure can be used to identify and eliminate waste.
They literally stand for five "s" words - Japanese originally - and assist in work place organization and
standardization of work
procedures. The steps in this structure include:
- Sort (Seiri): Eliminate unnecessary items from the workplace.
Method: Tag items that are believed to be unnecessary, move them to a central location, and then reuse or eliminate them.
Example: An excessive number of unused wheelchairs are moved into storage to be used for emergencies only. - Set in Order (Seiton): Efficient and effective storage methods.
Method: "A place for everything, and everything in its place."
Example: All surgical supplies are maintained according to specific diagrams for each operating room in locked, sterilized cabinets. - Shine (Seiso): Clean and maintain.
Method: "Clean thoroughly, clean often." Establish a daily cleaning routine. Identify maintenance issues along the way.
Example: Operating rooms are cleaned within 15 minutes after the completion of surgery and restored to a pristine environment. - Standardize (Seiketsu): Establish best practices.
Method: Establish a routine, identify ownership, and solicit employee
input.
Example: Nurse scheduling is given to the senior nursing staff who best understands the needs of
each department, balanced with the need to retain quality nurses. - Sustain(Shitsuke): Continue the improvement for life.
Method: Change the clutter culture. Establish a new standard of workplace organization; reward accordingly.
Example: A hospital implements a program to instill a continuous improvement mindset and rewards employee suggestions that reduce waste or enhance profitability (Munro, Ramu, & Zrymiak, 2015, p. 8-9)
Pull Systems
A pull system is a lean manufacturing strategy used to reduce waste in the production process. In a push-based supply chain, products are pushed through the channel from production up to the retailers. In a pull-based supply chain, procurement, production, and distribution are demand-driven rather than based on predictions. Goods are produced in the amount and time needed (Koo, 2020). Another method is Constant Work in Progress (CONWIP) which is both push and pull.
Value Stream Mapping
A value stream map displays all the important steps of your work process necessary to deliver value from start to finish. It is also known as value stream analysis or lean process mapping. Review American Society for Quality What is Value Stream Mapping to learn more.
References
Kaizen Institute. (n.d.). What is Kaizen. Retrieved July 15, 2021 from https://www.kaizen.com/what-is-kaizen.html
Koo, J. (2020). Push System vs. Pull System. Tulip. Retrieved July 15, 2021 from https://tulip.co/blog/what-is-a-push-system-vs-a-pull-system/
Lean Manufacturing Tools (n.d.) OEE Calculation. Retrieved August 1, 2021 from https://leanmanufacturingtools.org/443/oee-calculation/
Lucidchart. (n.d.). The Best Lean Tools for Process Improvement. Retrieved July 9, 2021 from https://www.lucidchart.com/blog/best-lean-tools-for-process-improvement
Munro, R., Ramu, G., & Zrymiak, D. (2015). The Certified Six Sigma Green Belt Handbook. Retrieved July 12, 2021 from https://www.academia.edu/40442176/The_Certified_Six_Sigma_Green_Belt_Handbook_Second_Edition