Fishbone diagram analysis

Revision as of 18:02, 18 February 2021

Developed by Maria Konstantina Papaioannou

Abstract

Risk project management is a broad and complex field. It is well established that every project at every stage carries risk. Possible risks for a running or finished project are countless and may vary from anticipated to unexpected. In addition, their result ranges from minor inconvenience to disrupt of the project. Thus, identifying possible risks is a key challenge for every project. Once identified and listed those risks can be categorized using qualitative risk analysis. This article introduces the Ishikawa fishbone diagram as a method to analyze numerous reasons why a project may fail. The diagram provides a visualization that simplifies the identification of risks and categorizes them. It heavily relies on the idea that minor problems matter and can lead to causes that affect badly the existing project. It is commonly used by safety and reliability engineers to detect faults in constructions. Firstly, this article gives a historical overview of the diagram. It analyzes its basic components, provides detailed guidance to its building, and briefly presents its implementation on the Apollo 13 case. Additionally, the article displays the technique’s benefits and refers to its disadvantages. Finally, it reflects critically on its limitations and makes recommendations on how to maximize the diagram’s utility.

Description of Ishikawa fishbone diagram

Historical overview

Japanese organizational theorist Kaoru Ishikawa(石川 馨)was born in 1915 in Tokyo, Japan and he is considered key figure in the development of quality initiatives. (book Guide to Quality Control. Tokyo: Asian Productivity Organization) During the year 1968, while working as a full-time professor at the Faculty of Engineering at the University of Tokyo, Ishikawa studied the concept of quality and introduced the seven quality management tools for projects’ improvement in his book Guide to Quality Control. In the book Ishikawa explains thoroughly the concept and the utility of each of the following tools: Ishikawa diagram, the histogram, the Pareto chart, the check sheet, the control chart, the flowchart, and the scatter diagram. The book includes instructions on building and the reading the quality control techniques mentioned above. The Ishikawa diagram became increasingly popular since it is a simple visual technique for problem solving and is used until today in modern management projects.

Building the diagram

Ishikawa fishbone diagram is a technique that helps users visualize and sort numerous reasons why a project may fail. The Ishikawa diagram is also referred to as cause-and effect (CE) diagram because of its function. Most commonly it is referred to as the fishbone because of its unique shape. A completed fishbone diagram includes a central "spine" and several branches very similar to a fish skeleton. It can be implemented in various kinds of projects such as manufacturing, marketing and so forth. It combines brainstorming with a concept map and looks much, as the name suggests, like the skeleton of a fish. The head of the fish represents the problem of the project and the causes are connected with its spine that is the x-axis of the diagram.

To effectively build the fishbone diagram a group must carry out the steps that are presented below:

Step 1: Group members should brainstorm and agree on potential effects/near misses that might or had already threatened the success of a project. The problem statement will be placed later in the right side of the diagram and will be represented by the head of the fish.

Step 2: Each member should agree on the major categories of causes that lead to the problem. Though it is up to the team to select the causes’ categories, usually depending on the nature of the project, the most common categories used are: equipment, process, people, materials, environment, management.

Step 3: Identification of causes. The causes are organized under the category they are related with and are represented by lines that lean on the x axis as shown in figure 1.

Step 4: Identification of sub-causes. Sub-causes are branching off the cause branches. Those are represented by lines parallel to the spine of the fish. By continuous searching of the causes of the problem, the group generates deeper levels of them. It is noteworthy that one cause might match with more than one category. Through those line segments, representation can be simple, but it can become more complex by completing with qualitative and quantitative appreciations and risks that characterize each cause.

Step 5: Analyzing the diagram and developing of solutions to correct the causes and improve the process or product. Once the process is completed there will be numerous identified root causes -most likely too many to solve at once. Thus, at this point the team will need to select the root causes they wish to initially solve and target effort and resources on them.

The fishbone diagram implemented on the Apollo 13 incident

Benefits

Limitations

Recommendations

References

Limitations and suggestions

References