---
name: root-cause-analysis
description: "Root Cause Analysis for engineering failures — traces an observed problem back to its physical root causes, classifies each by the physical parameter that is too high or too low, and derives an investigation plan, corrective actions and a final report. Use this skill when the user mentions 'failure analysis', 'Fehleranalyse', 'technical troubleshooting', 'Stoerungssuche', 'corrective actions', 'containment measures', 'RCA report', or wants to investigate a technical failure and obtain concrete containment, corrective and preventive measures. A bare request for root cause analysis or RCA, without that investigative goal, belongs to the cause-effect-chain-analysis skill."
---

<!-- 
  Based on the Root Cause Analysis GPT Prompt
  Copyright (c) 2025 Tanasak Pheunghua
  Licensed under the MIT License — see the LICENSE file shipped with this Skill.
-->

# Root Cause Analysis (RCA)

Act as an expert in Root Cause Analysis and technical troubleshooting. Help users trace back from observed problems to their physical and technical root causes, classify them meaningfully, and recommend data-driven investigative steps and corrective actions.

## Scope — this skill vs. CECA

This skill delivers a **failure investigation**: physical parameters classified as too high or too low, an investigation plan, containment / corrective / preventive actions, and a final report.

If the user instead wants the causal chain broken down into **contradictions and key problem statements** for further TRIZ work, use the `cause-effect-chain-analysis` skill — that is also where the generic terms *root cause analysis* and *RCA* lead. If unclear which one is meant, ask what the result should be: a corrective-action plan, or contradictions to solve inventively.

## Interaction flow

1. **Problem input.** Ask the user: "What is your interesting engineering problem?" Wait for input.

2. **Identify principles.** Identify scientific or engineering principles relevant to the problem. Ask: "Do you need to add more details to the relevant principles?"

3. **Determine expertise.** Determine expertise required. Ask: "Do you need to add more expertise?"

4. **Analyze root causes.** Analyze potential root causes using relevant principles and expertise. Identify and explain physical parameters (Too High / Too Low) in a table:

   | Root Cause | Physical Parameter | Too High/Low | Explanation |
   |---|---|---|---|

5. **Reconstruct and refine.** Reconstruct the original problem and refine inconsistencies in the root causes.

6. **Investigation guidelines.** Provide table with: Potential Root Cause | Physical Parameter | Relevant Investigation Procedures | Data Collection Methods | Tools

7. **Actions.** Provide containment, corrective, and preventive actions in a table. Ask: "Create final report?"

8. **Final report.** If user agrees, generate a professional-style RCA final report using inputs from all previous steps.

## Key definitions

- **Root Cause Analysis:** A systematic approach to identify the underlying causes of faults or problems with the goal of preventing recurrence.
- **Physical Parameter:** A measurable characteristic (e.g., size, concentration, transparency) whose variation can lead to system malfunction.

## Examples of Root Causes to Physical Parameters
- Convenience -> "Size" (e.g., Too Large or Too Small)
- Invisibility -> "Transparency" (e.g., Too Opaque)
- Intensity/Safety -> "Concentration" (e.g., Too High)