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QHSE Glossary

Root Cause Analysis

A structured investigation method to identify the fundamental cause of a problem, not just its symptoms.

Root Cause Analysis

Root Cause Analysis (Systematic Investigation of Problems) is a critical concept in quality, health, safety, and environmental management.

What Is Root Cause Analysis?

Root Cause Analysis (RCA) is a systematic process for identifying the fundamental cause(s) of problems, nonconformities, or incidents — not just the symptoms. Effective RCA goes beyond immediate causes to identify systemic failures in management systems, processes, training, or culture. Common RCA methodologies include: 5-Why Analysis (Toyota Production System), Fishbone/Ishikawa Diagram (6M categories: Man, Machine, Method, Material, Measurement, Mother Nature), Fault Tree Analysis (Boolean logic), Failure Mode and Effects Analysis (FMEA), and 8D Problem Solving (8 disciplines). A good root cause is specific, actionable, and within management control to change.

Root Cause Analysis Requirements Under UK Law

ISO 9001:2015 Clause 10.2.1(b) requires organisations to evaluate the need for action to eliminate causes of nonconformity. AS9100 requires root cause analysis for all nonconformities. FDA 21 CFR 820.90 mandates investigation of causes of nonconforming product. ISO 45001:2018 Clause 10.2 requires investigation to determine root causes of incidents. HSE guidance HSG48 (Reducing Error and Influencing Behaviour) provides a framework for human factors RCA. The average cost of a quality failure in manufacturing: £2,500-£15,000 when caught internally, £25,000-£250,000 when caught by the customer.

Key Components of Root Cause Analysis

  • 5-Why Analysis
  • Fishbone/Ishikawa Diagram
  • Fault Tree Analysis
  • 8D Problem Solving
  • DMAIC (Six Sigma)
  • Pareto Analysis
  • Failure Mode and Effects Analysis (FMEA)
  • Kepner-Tregoe Problem Analysis

Root Cause Analysis in Practice

An electronics manufacturer identifies a 12% solder defect rate on a new PCB assembly line. Using Q-Hub's 8D template, the quality team: D1 forms a cross-functional team (3 engineers, 1 quality, 1 production). D2 defines the problem (solder bridges on 0.5mm pitch QFP components). D3 implements containment (100% visual inspection). D4 conducts root cause analysis using fishbone diagram — identifying 3 contributing factors: wave solder temperature 2°C below spec, flux density at lower control limit, and conveyor speed increased 15% without engineering change order. D5-D7 implement permanent corrections. D8 verifies: defect rate drops to 0.3% within 2 weeks.

How to Manage Root Cause Analysis with Q-Hub

Q-Hub provides comprehensive tools for Root Cause Analysis management. The Capa Management module handles the core requirements, integrated with document control, audit scheduling, training management, and KPI dashboards to ensure your Root Cause Analysis processes are audit-ready at all times.

Related Terms

Want to see how Q-Hub handles Root Cause Analysis in practice? Book a demo or see pricing.

Related QHSE Terms

  • AS9100 — The aerospace quality management standard, based on ISO 9001 with additional requirements for aviati
  • Audit — A systematic, independent examination of processes, products, or systems to verify compliance with d
  • Bow-Tie Analysis — A visual risk assessment method that maps the causes of an event, the event itself, its consequences
  • CAPA — Corrective and Preventive Action — a systematic approach to investigating root causes of non-conform
  • COSHH — Control of Substances Hazardous to Health — UK regulations requiring employers to control exposure t
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