How to get the most out of the cause and effect diagram Simple hypothesis testing, such as asking "Where?", "When?", and "How?" lead to a better understanding of the relationship beween the potential cause and the problem the team is tasked to solve.
In certain instances, the team might collect additional data to better understand and quantify the potential causes. It is not unusual for teams to use techniques such as multi-voting to shortlist the areas that will have lasting impact on solving the problem at hand. The team then should focus more specifically on the potential cause(s) that have a high probability of taking place. Remember that these reasons are free-flowing, form logical patterns and are inter-connected to a key cause.Īt the end of step three, your team should have a good overview of the possible causes for the problem or event if there are areas in the chart where possible causes are few, see if your team can dig deeper to find more potential causes. These suggestions should be written down and connected to their appropriate key cause arrow (see the image below). To facilitate participation from all of your team members, ask each member of the group to provide one reason behind a key cause. Tools such as the five Whys (the subject of a future column) can help your team to drill down to these sub-causes. The goal in this step is to brainstorm as many causes for each of the key causes. Identify the reasons behind the key causes The image below shows how to visually depict these key causes on the cause and effect diagram. Other appropriate primary causes include service, quality, technology, consumables, work processes, environment, service level, etc. Some of the commonly used primary causes, but not limited to, include the four M's of manufacturing (machine, method, material and manpower) the four S's of the service sector (surroundings, suppliers, systems and skills) the five M's (measurement, maintenance, money, management and Mother Nature) and the eight P's of marketing (product, price, place, promotion, people, process, physical environment and productivity). Often these causes are put in categories such as people, equipment, materials and external factors. In this step, the primary causes of the problem are drilled down by using brainstorming techniques.
Identify the key causes of the problem or event On the cause and effect diagram the problem is visually represented by drawing a horizontal line with a box enclosing the description of the problem on the tip of the arrow.
While defining your problem or event, your problem statement may also contain information about the location and time of the event. This first step is probably one of the most important tasks in building a cause and effect diagram. How to construct a cause and effect diagram step-by-step Define the problem (effect) to be solved. Variations of this method include the cause enumeration diagram, the cause and effect diagram with the addition of cards (CEDAC) and a desired-result fishbone diagram. One of the seven basic quality tools, the cause and effect diagram is also know as the fishbone diagram (as the key causes look like the bones of a fish when displayed visually, hence the name) and the Ishikawa diagram (named after Kaoru Ishikawa, who first proposed the tool). The tool lends itself to enabling a team to readily organize the causes behind the problem into useful categories, providing a structured brainstorming session. The cause and effect diagram is an easy yet powerful tool commonly used in a cross functional setting to visually describe the potential root causes for a specific problem in question.