The fishbone diagram is a useful tool for determining cause and effect and diagraming the 5-Why process. Also known as Ishikawa diagrams (named for its creator) or herringbone diagrams, they typically include universal categories that contribute to problems:
Equipment: Any machines, computers (hardware or software) or tools needed to complete the process.
Materials: Any raw materials that are needed to complete the process. Input data can be considered a raw material.
Environment: Physical surroundings in which the process occurs that include temperature, humidity, air quality and culture.
Process: How the task is completed. Process factors include specific requirements including policies, procedures, rules, regulations and laws.
People: Anyone who has a role in carrying out the process.
Management: Supervisors and upper management personnel who are responsible for setting policies and approving budgets and expenditures
The six capstones, or main fish bones, are the main groupings of potential causes. (Some variations substitute "Cause 1, Cause 2" etc. as the capstones.) The detail of each cause is noted on the minor fish bones.
When constructing your fishbone chart, it's helpful to get as many people involved in identifying causes as feasible. Diversity can often provide a quicker solution. It also provides a sense of ownership of the problem, and ownership ignites the solution-finding fire. Also, keep in mind that creating a fishbone diagram is really a brainstorming exercise. Make note of all the ideas regarding contributing causes.
Finally, when the chart is complete, test its logic. The problem happens because of this, this happens because of F, F happens because of E, E happens because of D, D happens because of C, C happens because of B, and B happens because of A. You should be able to track the problem back through each of the major and minor fish bones. Don't skip the logic test. In the heat of brainstorming, it's easy to get a bit off track and possibly created a logic misstep. Without testing, you may end up chasing the wrong solution.
|