Root Cause Analysis in Quality Assurance

Correct Answer: Fault Tree Analysis (FTA) with probability calculations

Fault Tree Analysis (FTA) with probability calculations is the most comprehensive analytical framework for Root Cause Analysis in complex systems because: 1. It provides a systematic, top-down approach to identify all potential causes of system failure 2. It uses Boolean logic to show the relationships between different failure modes 3. It incorporates probability calculations to quantify the likelihood of each failure path 4. It can handle both hardware and human error factors in the analysis 5. It allows for both qualitative and quantitative assessment The other options are less comprehensive: Process Capability Index is primarily focused on process performance and variation, not comprehensive system failure analysis. Sequential Event Chain Analysis is linear and may miss complex interactions between different failure modes. Bayesian Network Analysis, while powerful for conditional probabilities, is better suited for decision-making under uncertainty rather than comprehensive failure mode analysis.

Correct Answer: 5 Whys Analysis

5 Whys Analysis is the correct technique used in Root Cause Analysis. This technique involves asking 'Why?' typically five times in succession to drill down to the root cause of a problem. It is a simple yet powerful tool that helps identify the underlying cause rather than just addressing surface-level symptoms. The other answers are incorrect because: - 'Iterative Problem Decomposition Method' is an overly complex name for a simple concept and is not a standard industry term - 'Continuous Interrogative Investigation Technique' is a made-up term that attempts to describe the process in unnecessarily complex language - 'Root Factor Exploration System' sounds formal but is not a recognized technique in professional analysis The 5 Whys Analysis is widely recognized in project management, lean manufacturing, and business analysis as an effective troubleshooting method. It was originally developed by Sakichi Toyoda for Toyota Motor Corporation.

Correct Answer: To identify and categorize potential causes of a problem into different categories like methods, materials, and machines

An Ishikawa (Fishbone) Diagram's primary purpose is to identify and organize potential causes of a problem into distinct categories, typically using the 6M framework: Methods, Materials, Machines, Manpower, Measurements, and Mother Nature (Environment). This diagram helps teams visualize all possible causes of a problem in a structured way, making it easier to analyze complex issues and identify root causes. The visual representation resembles a fish skeleton, where the main problem is at the 'head' and the potential causes branch out like 'bones.' The other options are incorrect because: - Creating chronological sequences is the purpose of timeline analysis or process flow diagrams, not fishbone diagrams - Mathematical modeling of process variables is more aligned with statistical analysis tools like regression analysis - Stakeholder mapping and influence analysis is a different tool used in stakeholder management, not root cause analysis