The Eight Disciplines of Problem Solving (8D) is a problem solving methodology designed to find the root cause of a problem, devise a short-term fix and implement a long-term solution to prevent recurring problems. When it’s clear that your product is defective or isn’t satisfying your customers, an 8D is an excellent first step to improving Quality and Reliability.
Ford Motor Company developed this problem solving methodology, then known as Team Oriented Problem Solving (TOPS), in the 1980s. The early usage of 8D proved so effective that it was adopted by Ford as the primary method of documenting problem solving efforts, and the company continues to use 8D today.
8D has become very popular among manufacturers because it is effective and reasonably easy to teach. Below you’ll find the benefits of an 8D, when it is appropriate to perform and how it is performed.
D0: Plan – Plan for solving the problem and determine the prerequisites.
D1: Use a team – Select and establish a team of people with product/process knowledge.
D2: Define and describe the problem – Specify the problem by identifying in quantifiable terms the who, what, where, when, why, how, and how many (5W2H) for the problem.
D3: Develop interim containment plan; implement and verify interim actions – Define and implement containment actions to isolate the problem from any customer.
D4: Determine, identify, and verify root causes and escape points – Identify all applicable causes that could explain why the problem occurred. Also identify why the problem was not noticed at the time it occurred. All causes shall be verified or proved, not determined by fuzzy brainstorming. One can use 5 Whys and cause and effect diagrams to map causes against the effect or problem identified.
D5: Choose and verify permanent corrections (PCs) for problem/nonconformity – Through preproduction programs, quantitatively confirm that the selected correction will resolve the problem for the customer.
D6: Implement and validate corrective actions – Define and implement the best corrective actions (CA).
D7: Take preventive measures – Modify the management systems, operation systems, practices, and procedures to prevent recurrence of this and all similar problems.
D8: Congratulate your team – Recognize the collective efforts of the team. The team needs to be formally thanked by the organization.