Through user acceptance testing, a software flaw was identified.

A fishbone diagram, also known as a cause-and-effect diagram or an Ishikawa diagram, is a tool that helps to identify and analyze the possible causes of a problem or an effect. It can help the business analyst to perform a root cause analysis in order to analyze and resolve the discrepancy identified through user acceptance testing. A fishbone diagram has a structure that resembles a fish skeleton, with a head, a spine, and several branches. The head represents the problem or the effect, the spine represents the main cause categories, and the branches represent the sub-causes or factors that contribute to the problem or the effect. By creating a fishbone diagram, the business analyst can brainstorm and organize the potential causes of the software flaw, and then investigate and verify the most likely root cause. A fishbone diagram can also help to communicate the findings and recommendations to the stakeholders and the development team. An interface analysis is a tool that helps to identify and describe the interactions and dependencies between different components or systems. It does not help to perform a root cause analysis in order to analyze and resolve the discrepancy identified through user acceptance testing, as it does not focus on the causes and effects of the problem. A Delphi estimation is a tool that helps to obtain a consensus among a group of experts on a complex or uncertain issue. It does not help to perform a root cause analysis in order to analyze and resolve the discrepancy identified through user acceptance testing, as it does not provide a systematic and structured way to identify and analyze the causes of the problem. A functional decomposition is a tool that helps to break down a complex system or process into smaller and simpler components or functions. It does not help to perform a root cause analysis in order to analyze and resolve the discrepancy identified through user acceptance testing, as it does not show the relationships and influences between the components or functions. References: PMI Professional in Business Analysis (PMI-PBA)® Examination Content Outline1, PMI Guide to Business Analysis2, Business Analysis for Practitioners: A Practice Guide3, Root Cause Analysis: Definition, Examples & Methods | Tableau1