The purpose of the Fishbone technique is to facilitate the analysis of existing processes to determine opportunities for improvement. Ishikawa (1982) describes Fishbone as a way to examine the causes of failure of manufacturing systems to produce goods at the level of quality desired.
A basic fishbone diagram, will show the head of a fish at the right side of the page and the spine and ribs extending to the left. The opportunity, or problem is written on the head. Because Ishikawa was working in quality control in manufacturing, labels that he placed on the ‘ribs’ above and below the spine were ‘materials’, ‘methods’, ‘machines’, and ‘workers’. Although other ribs could be included in a fishbone diagram, generally the number of ribs is kept under ten.
This technique is used in groups of usually 6-12 people who are familiar with the problem or opportunity. More than one group may be used, either at different times or concurrently in different rooms or sections of a large room. A facilitator is necessary for each group.
Materials needed are a large diagram of the fish skeleton drawn on paper and displayed on a wall or easel where everyone can easily see it, coloured marker pens, and pads of paper and pencils.
The fishbone displays the general need, and several ribs selected by the needs assessor are drawn and labelled before the session (An alternate method is for the ribs to be drawn in before the meeting, but not labelled until later, see description that follows).
Specialists can be asked to add value either during the development of the fishbone or by providing comment after it has been developed (see Specialist Questioning Technique).
Steps
Set clear boundaries.
Negotiate the problem / opportunity. It is often useful to express this as a Focus or Focusing Question.
Each person then individually writes down as many responses to the Focusing Question as are possible from her/his perspective. (This could be the time when the facilitator writes in the labels for the ribs. It is better if the group members do not think about the labels of the ribs as they generate lists of causes).
Each person places their contributions on the diagram (without comment or discussion).
Discussions are focused on understanding the ideas and identifying and filling gaps.
The group then reviews the diagram to decide whether it needs restructuring.
The facilitator writes in the changes until there is agreement that the relationships of the causes to the ribs are generally accurate.
Points of leverage for improving the problem / opportunity can be identified by giving participants specific criteria and scores to rank the key causes / opportunities for improvement. For example, ask the participants to identify those opportunities that will have most benefit (impact) and give each participant a total of 6 votes to place on each of 6 different opportunities (one per item). Coloured pens or coloured sticky dots can facilitate the recognition of clusters of priorities.
Finally, there is general discussion of the fishbone diagram. If the group members work at the site of the meeting (e.g. teachers in a school or employees of a business), the diagram can be posted on a wall for a period of time so that concerned people can think about the decisions.