An investigation into all identified potential causes is necessary for effective problem solving. A cause and effects diagram can be used to brainstorm all potential causes of the described problem. The team should decide on what C&E diagram(s) is to be used: 5M, Process Flow and/or stratification. The more detailed the C&E diagram, the higher the chances the root cause will be included on the C&E diagram. An effective C&E diagram will include input from all team members and will be discussed in detail.
Any existing data should be reviewed for clues to potential causes. Further data collection may be required to investigate additional causes.
If the problem has not previously been seen, a timeline analysis should provide significant data. The timeline will identify events occurring about the time the problem developed. If enough documentation is available, potential causes can be further identified. For example, if a new operator was put on a process or if a new supplier began supplying parts. Investigation into the events occurring at the same time the problem was discovered could lead to several important potential causes.