A handy technique for the purpose of a root cause analysis on a specified challenge is a fishbone diagram. A cause and effect chart motivates co-workers to function methodically and to search past the totally obvious reasons for a dilemma. The construction of the cause and effect chart makes it possible for prospective root causes to be discovered in a methodized approach.
The fishbone chart often known as an Ishikawa diagram after Dr. Kaoru Ishikawa, the Japanese quality control expert who invented it. The well-known term, "fish bone" comes from the fact that the chart has a resemblance to a fish skeleton.
Cause and effect analysis starts off with circumstances to be examined. The problem is documented as a question on the right hand side of a page. Then, an arrow, or at times a representation of a fish head, points to the circumstance to be analyzed. Off to the left of where the concern is mentioned, a horizontal line bifurcates the paper into two sections. This forms the spine of the fishbone chart.
The next set of bones shows the key categories of factors which might lead to the root cause. The names of these cause categories are written along the top and bottom of the page. Arrows point back to the backbone as well as towards the head, thus forming a herringbone pattern.
There are six standard categories for manufacturing problems: material, machine, maintenance, methods, man and mother nature. There are some other categories that can be used like equipment, environment, process, and leadership that are added on to this if your situation calls for it. Experts use several factors to analyze service and administrative problems such as: price, promotion, processes, place, policies, procedure and the product. A service industry for example would use the following factors to figure out problems: surroundings, suppliers, systems and skills. This is why conventions were devised to provide categories to help determine the problem areas in these categories.
Analysis is undergone once the fundamental skeletal structure is in place. Variables are listed that have an impact in each subset of elements that contribute to the root cause. These are displayed on top of arrows directing you to the subset lines, which themselves may possess lines of their own, further outlining the variables that have an impact. While this may proceed ad infinitum, naturally it will be hard to sketch more than a few levels.
The reasons which causes the end result is analyzed by a team through brainstorming each category, using the skeleton of the diagram. With reference to the context of each category, a question is formed according to the problem and asked the team members to answer them. Generally questions like "What made this happen?" are asked and according to the category the question varies to "How do factors influence this category?"
Team members brainstorm more items to add to the diagram. When they run out of ideas, the brainstorming stops. Then the results are studied in order to find the likeliest cause of the problem. If the same issue appears in multiple categories, it if fair to assume that this is an important root cause. Areas of the diagram are also studied as these areas may also point to something significant.