This Blank Fishbone Diagram Template can be used to investigate the potential causes of a specific problem, allowing your team to find a more effective solution. After brainstorming some ideas, group them into groups to narrow down the root cause of the problem. When you need to rely on experience and ideas rather than quantitative data, a Blank Fishbone Diagram Template comes in handy. In 1943, Kaoru Ishikawa, an engineer and professor at the University of Tokyo invented the Fishbone Diagram. Ishikawa's diagram is based on the assumption that an error or inefficiency causes every problem.