Cause & Effect Diagram

Cause & Effect Diagram

The cause & effect diagram is the brainchild of Kaoru Ishikawa, who pioneered quality management processes in the Kawasaki shipyards, and in the process became one of the founding fathers of modern management. The cause and effect diagram is used to explore all the potential or real causes (or inputs) that result in a single effect (or output). Causes are arranged according to their level of importance or detail, resulting in a depiction of relationships and hierarchy of events. This can help you search for root causes, identify areas where there may be problems, and compare the relative importance of different causes.

Causes in a cause & effect diagram are frequently arranged into four major categories. While these categories can be anything, you will often see:

• manpower, methods, materials, and machinery (recommended for manufacturing)
• equipment, policies, procedures, and people (recommended for administration and service).

These guidelines can be helpful but should not be used if they limit the diagram or are inappropriate. The categories you use should suit your needs. At SkyMark, we often create the branches of the cause and effect tree from the titles of the affinity sets in a preceding affinity diagram.

The C&E diagram is also known as the fishbone diagram because it was drawn to resemble the skeleton of a fish, with the main causal categories drawn as "bones" attached to the spine of the fish, as shown below.

Cause & effect diagrams can also be drawn as tree diagrams, resembling a tree turned on its side. From a single outcome or trunk, branches extend that represent major categories of inputs or causes that create that single outcome. These large branches then lead to smaller and smaller branches of causes all the way down to twigs at the ends. The tree structure has an advantage over the fishbone-style diagram. As a fishbone diagram becomes more and more complex, it becomes difficult to find and compare items that are the same distance from the effect because they are dispersed over the diagram. With the tree structure, all items on the same causal level are aligned vertically.

To successfully build a cause and effect diagram:

1. Be sure everyone agrees on the effect or problem statement before beginning.
2. Be succinct.
3. For each node, think what could be its causes. Add them to the tree.
4. Pursue each line of causality back to its root cause.
5. Consider grafting relatively empty branches onto others.
6. Consider splitting up overcrowded branches.
7. Consider which root causes are most likely to merit further investigation.

Other uses for the Cause and Effect tool include the organization diagramming, parts hierarchies, project planning, tree diagrams, and the 5 Why's.

Cause & Effect Diagram or Tree Diagram Tool

PathMaker's cause and effect diagram, or Ishikawa diagram tool helps users discover the root causes of problems. The traditional fishbone shape has been superseded by a right-angled structure, which is easier to construct, read and use. Zooming in and out permits viewing either the forest or the trees. Branches can be collapsed and expanded, and the tree can flow from left to right or vice-versa. You can auto-fit text, adjust spacing, change colors, edit via drag and drop, and more.

Diagrams may be built from scratch or from data copied from a brainstorm and affinity diagram. This tool can also be used as a tree diagram, a contingency planner (PDPC Chart), a classifier and an organization chart maker.