Fishbone Diagram: Best Choice for Six Sigma Root Cause Analysis

Plan Do Check Act

As you commence the fishbone analysis to find the root cause, ensure that you discover and then keep track of the categories for your problem. Define the problem precisely then take time to address all conceivable causes. No idea is ignored during this part. Causes can be apparent or even unlikely and even tricky to describe. Consider employing brainstorming sessions in order to discover a wide array of factors. Appreciate that some causes may just be a matter of opinion while some are completely supported by statistics, details, or diagrams, along with Pareto charts.Full engagement of various experts is required to pull together the list of inputs. From all the impacted processes and departments, there should be management and front-line representatives in this group. After the starting of this, the potential improvements to the products, services or processes can be kicked off.

Through the process of recognizing inputs, we develop a fishbone diagram. Rather than specifically going for a good-looking diagram we should concentrate on all of the important inputs. With the recognition of each input, some additional reasons are also identified. The shape of the diagram comes from branching of larger bones which are due to additional inputs. As the process continues, branching goes to several levels on the Ishikawa diagram. Every cause is represented by a small bone. The following categories are regularly used in a 5m fishbone manufacturing scenario:

1. Measurement – including using measuring devices from the kaizen manufacturing concepts to identify source causes and defects under that scope.
2. Man – Brainstorming exercises have many benefits including identification within a specific section as a support in the implication on the causes started by the people inside a particular step.
3. Machine – To precisely trace the origin of the machine defect it is crucial for one to figure out whether one or multiple machines are to blame. Machine defect sources should therefore include the defect sources from machines in the entire working environment.
4. Method – encourage reflection upon matrix organizational procedures. Often minimizing the occurrence of defects can be as simple as making slight changes to procedure. Routines can make people blind to inefficiencies and problems. When ingrained routines are broken up, it becomes easier to see these opportunities for improvement and product benefits from increased book quality.
5. Material – including any raw materials or other pieces requiring quality review during the process. At times, material used in the work stream may be the cause of defects identified by the end of the manufacturing process.
6. Environment – Quality of work scorecard is generally affected by environment. The cause of negative effect due to environmental factors has to be analyzed and moderated positively.