Learn the in’s and out’s of DMAIC and DMADV, including individual methods, quality control standards and industry trends, with these articles from Six Sigma Daily – your source for Six Sigma news and information.
A Cause and Effect Diagram is a graphical tool for displaying a list of causes associated with a specific effect. It is also known as a fishbone diagram or an Ishikawa diagram (created by Dr. Kaoru Ishikawa, an influential quality management innovator). The graph organizes a list of potential causes into categories.
There are four possible outcomes when making hypothesis test decisions from sample data. Two of these outcomes are correct in that the sample accurately represents the population and leads to a correct conclusion, and two are incorrect, as shown in the following figure:
Below is a decision tree for the most commonly used hypothesis tests:
The Standard Deviation of a set of data describes the amount of variation in the data set by measuring, and essentially averaging, how much each value in the data set …
The service world has recognized the value of poka-yoke during the last several years. One way of applying error-proofing (poka-yoke) in the service sector is to devise a “task” poka-yoke. A task poka-yoke concentrates on the tasks that a server must perform and devises methods to assure the task is completed correctly. A popular example of a task poka-yoke is the automatic change dispenser that you encounter in many stores.
A small assembler provides wiring harness assemblies for a particular automotive electronic controller. There are several part numbers and many of the parts for each part number look very much alike. So it isn’t surprising that the company has received complaints from the automotive assembly plants that some harnesses have incorrect components (which have to be changed out on the assembly line causing delays).
Poka-yoke (poh ka yoke) is a mistake-proofing approach to eliminating errors that was developed by the Japanese engineer Shiego Shingo in the 1960s. The word “poka-yoke” is derived from a Japanese word that means “to avoid errors.” Poka-yoke makes use of simple but effective tools and signals to prevent errors from occurring.
A Prioritization Matrix is typically an L-shaped matrix which makes pairwise comparisons of established criteria and options. The prioritization matrix is a rigorous method and requires skill to use effectively. It is also applicable to many situations and has several different configurations. To be used effectively, the criteria and the options must be clearly developed and a scheme for weighing them must be applied.
An Affinity Diagram is an analytical tool used to organize many ideas into subgroups with common themes or common relationships. The method is reported to have been developed by Jiro Kawakita and so is sometimes referred to as the K-J method.
An Activity Network Diagram is a diagram of project activities that shows the sequential relationships of activities using arrows and nodes. An activity network diagram tool is used extensively in and is necessary for the identification of a project’s critical path (which is used to determine the expected completion time of the project).
