​Normal distribution is a statistical representation where most distributions that are observed are relatively close to one mean (average).  If there is deviation associated with the mean, which there normally is, the deviation remains almost identical on the plus side as the deviation on the minus side.  When normal distribution is graphed (histogram) it generally takes the shape of a bell showing "normal" or even distribution from the mean. 

  The term supermarket or grocery store in lean six sigma refers to a predetermined market (storage/inventory).  The supermarket carries the necessary "supplies" for a work area that is close by.  When a customer (internal/external) needs an item they can retrieve the item from the supermarket.  The supermarket then replenishes or restocks their supplies based on the downstream demand.  Supermarkets prevent overstocking and help lower inventory levels.  

  Standard work in process is the minimum necessary level of items or materials needed to maintain the proper flow in a production environment.

  Special Causes of Variation is when something happens to cause a variation in the output (Y) that is unusual and is not consistent or constant.  Special causes of variation are often referred to as assignable causes because they can be eliminated with a response or a solution to individual variations.  Control Charts can be used to differentiate between common causes and special causes of variation.

  Example:  In the photo above three arrows hit the target dead center.  One arrow hit the target high and to the left.  The arrow that landed high and to the left is an example of a special cause of variation.

  Setup Reduction refers to a decrease in the changeover time.  The setup reduction attempts to reduce every possible second from the changeover or setup time.  Because the changeover or setup is not transforming any materials or services that a customer has agreed to pay for, both setup and changeover can be considered a form of waste/muda.  In most cases a setup reduction can reduce the setup time by 50% or more.

Solutions:
  The ©REDUCE methodology by Lean Strategies International LLC is a systematic way of reducing both setup and changeover times.  For more information on the ©Reduce Methodology visit our recent blog post on Listen to the Gemba, Changing things around.

  Mixed-Model Production is the practice of making, assembling or producing several different parts or products (this can also be applicable to services) in varying lot sizes so that the organization produces close to the same mix of products/services that will be sold on the same day.  The goal of a mixed-model production tactic is to smooth out the demand of upstream workcenters, cells, suppliers and vendors which results in a reduced inventory, faster changeovers and more accurate replenishment of products ultimately working towards building and or producing in accordance with daily demand.

  The purpose of Lean Accounting is to support the lean enterprise as a business strategy. It seeks to move from traditional accounting methods to a system that measures and motivates excellent business practices in the lean enterprise.  Applying Lean principles is part of this system.

The Vision for Lean Accounting

1. Provide accurate, timely, and understandable information to motivate the lean transformation throughout the organization, and for decision-making leading to increased customer value, growth, profitability, and cash flow.
2. Use lean tools to eliminate waste from the accounting processes while maintaining thorough financial control.
3. Fully comply with generally accepted accounting principles (GAAP), external reporting regulations, and internal reporting requirements.
4. Support the lean culture by motivating investment in people, providing information that is relevant and actionable, and empowering continuous improvement at every level of the organization.

​Ref: Wikepedia, Lean accounting

  A lead time ladder is the timeline shown on the bottom of a value stream map.  The lead time ladder is used to calculate the production lead time.

  Kaizen is the Japanese term for continual improvement.  The word kai means "change" and the word "zen" means good.  Continuous improvement involves an entire organization.  

See also:

• Kaizen Event
• Kaizen Blitz

  The House of Quality, is a diagram whose structure resembles that of a house.  The tool aids in determining how a product/service is living up to customer defined attributes. Although quite intricate, it is capable of storing a lot of information and comparing large amounts of data used for defining the relationship between customer desires and the firm/product capabilities.  The house of quality works through a six step process:
​

1. Identify customer attributes (voice of the customer).
2. Identify supporting features and generate those attributes. 
3. Comparision of requirements and design requirements .
4. Assign priorities to customer requirements and technical features.
5. Benchmark or evaluate competitors.
6. Identify technical features that will be deployed in the final product/service design.

  The house of quality is part of the quality function deployment (QFD) process and forces engineers, designers and developers to think about customer needs.  The house also helps teams in creating a crossfunctional design so that probelms are not built into a new service or part.