Icons for Lean Value-Stream Mapping

The Value-Stream Map (VSM) is a Lean tool used to express and define the actions, information, timing, and events in the value stream. When you create the Value-Stream Map, use the conventions for drawing each icon that illustrates an event, activity, or element. The standard icons used in a VSM are

Types and Forms of Waste in Lean

The essence of Lean is to reduce waste and get more to satisfy customers. Sources of waste exist everywhere, and waste shows up in many different ways.

Types of waste

Three Ms describe the waste in Lean:

• muda: Waste; any activity that does not add value

  Type-1 muda: Non-value-added, but necessary for the system to function

  Type-2 muda: Non-value-added and unnecessary for the system to function; the first targets for elimination

• mura: Waste due to unevenness or variation

• muri: Waste caused by overstressing people, equipment, or systems

The seven forms of waste

Known also as the seven mudas or seven wastes, these forms of waste were identified by Taiichi Ohno, a pioneer of the Toyota Production System.

• Transportation: Is there unnecessary (non-value-added) movement of parts, materials, or information between processes?

• Waiting: Are people, parts, systems, or facilities idle, waiting for a work cycle to be completed?

• Overproduction: Are you producing sooner, faster, or in greater quantities than the customer is demanding?

• Defects: Does the process result in anything that the customer would deem unacceptable?

• Inventory: Do you have any raw materials, work-in-progress (WIP), or finished goods that are in excess or not having value added to them?

• Movement: Do you move materials, people, equipment, and goods unnecessarily or excessively within a processing step?

• Extra processing: Do you have work being performed beyond what is required to satisfy the customer standards or requirements?

The Kaizen Project PDCA, or PDSA, Cycle of Lean

The term Kaizen is derived from two Japanese characters; kai, meaning “change” and zen meaning “continuous improvement.” Eliminating waste in the value stream is the goal of Kaizen. The PDCA (or PDSA) Cycle is the Lean working structure –the system for executing Kaizen. The acronym stands for:

1. Plan.

   Create a plan for change, identifying specifically what you want to change. Define the steps you need to make the change, and predict the results of the change.

2. Do.

   Carry out the plan in a trial or test environment, on a small scale, under controlled conditions.

3. Check (or study).

   Examine the results of your trial. Verify that you’ve improved the process. If you have, consider implementing it on a broader scale. If you haven’t improved the process, go back and try again.

4. Act.

   Implement the changes you’ve verified on a broader scale. Update the standard operating procedures.

Japanese Terms Used in Lean

The Lean process is full of Japanese terms — small wonder since it's a product of studying the Toyota Production System. Study these Japanese terms to better understand the Lean process:

• andon: A signal to alert people to problems in a process

• gemba: Where the action occurs

• genchi genbutsu: Go and see

• heijunka: Smoothing; the technique of leveling schedules

• hoshin: A system of planning, forms, and rules

• jidoka: Stopping machines when an error has been detected, preventing defects from progressing through the process

• Kaikaku: Radical improvement.

• Kaizen: Incremental, continuous improvement

• kanban: A signal system used to trigger replenishment

• poka-yoke: A device to prevent defect production

• sensei: A master or teacher

What Does Lean Mean to Manufacturing?

Lean is a manufacturing method for improving effectiveness and eliminating waste in order to produce increasing customer value and satisfaction. These principles and practices are important to Lean:

Definition of a value-added activity

A value-added activity needs to have the following standards:

• It must transform the product or service.

• The customer must be willing to “pay” for it.

• It must be done correctly the first time.

5S method of the workplace

The 5S method is a good way to establish organized flow. The 5S steps are:

• Sort: Organize the workplace. Dispose of all unnecessary items.

• Straighten: Arrange all remaining items in standard locations that can be easily and readily accessed.

• Scrub: Keep all equipment and working areas neat and clean.

• Systematize: Create a system to maintain order in the area as a regular part of the daily activities.

• Standardize: Exercise discipline to maintain cleanliness in the workplace and find ways to enhance/improve the process.

Lean fundamentals

The basic principles of Lean:

• Focus on the customer.

• Improve the value stream.

• Maintain flow.

• Pull through the system.

• Strive for perfection.

• Respect people