Summary
Root cause analysis tools are structured thinking methods to help uncover causes. The fishbone diagram plots causes along predetermined axes to methodically think through different types of causes. The DuPont tree identifies drivers for a specific outcome to determine levers to use to impact that outcome.
Root Cause Analysis Tools
Good old root cause analysis tools are useful to know To be honest, I don't use these tools all that much, but knowing them can be useful if you have some complex problems you want to diagnose. Most of the time, the teams I work with don't have the patience to go through this level of analysis. However, if you are dealing with manufacturing problems or problems with regulatory impact, these tools are a great way to diagnose and document at the same time.
Fishbone or Cause and Effect or Ishikawa Diagram
The purpose of this diagram is to systematically review all the potential causes and sub-causes of a problem and document them in an easy-to-understand format. For manufacturing, the major axes are called the five Ms - Man, machine, material, methods, and milieu (environment.) For services industries, the axes are the five Ps - People, processes, policies, place/plant/technology, and product. However, you can add or eliminate any axes you think are appropriate.
The DuPont tree
Developed by DuPont, this decision tree is used to find the drivers of a specific outcome, usually some sort of measure. For instance, the top level drivers of profits are revenues and costs. The purpose of the tree is to help determine which drivers are controllable and which drivers have the most impact on the outcome you want. Using profits, costs are more controllable than revenues and are used to improve profits when the revenues are disappointing.
Here's an example for company that wanted to improve its economic value-added (EVA) which is a financial measure of a company's performance based on the residual wealth calculated by deducting cost of capital from its operating profit. It helps show how effectively a company is using its assets.