Fishbone diagram template

One effect, many labeled causes

A fishbone diagram (Ishikawa diagram, cause and effect diagram) puts a single problem in the head of the fish and groups suspected causes along bones. Kaoru Ishikawa used it in quality work. The template is the skeleton plus category names. A fishbone diagram template in a slide or in Word is the same skeleton: a horizontal spine, diagonal bones, and short phrases on the bones.

Common category sets are the 6 Ms used in manufacturing: people (man), machine, method, material, measurement, and environment (mother nature). A school or an office can rename the bones. The rule is that every note is a possible cause of the one effect in the head, not a general complaint.

Example: the lunch line runs long

Effect, written at the head: 'Lunch line exceeds 12 minutes.' People: one cashier on duty. Method: cash and card on the same till. Machine: the card terminal restarts mid-line. Material: the popular tray is assembled only after the bell. Measurement: nobody records the wait, so the 12-minute claim is a guess until someone times three days. Environment: three grades are released at the same minute.

The diagram does not pick a fix. It stops the team from arguing about a new menu when the notes cluster on the bell schedule and the single till. A fix discussion can move to a process map of the line, or to a decision tree if two remedies compete.

Steps

1. Write the effect as a measurable phrase. Include a number or a visible symptom. 'Things are bad' cannot be the head.
2. Choose four to six bones. Use the 6 Ms or rename them. More than six bones and the poster becomes a list.
3. Ask 'why' once on each note. A bone that says 'people' is a category. A note that says 'one cashier after 12:10' is a cause.
4. Circle clusters, do not rank yet. If four notes sit on one bone, that bone is where to look first. Ranking comes after you have evidence.