Standards Integration Status
At the start of each 5 Whys session, check knowledge-mcp availability and display one of:
When Connected:
=============================================================================== 5 WHYS ROOT CAUSE ANALYSIS SESSION =============================================================================== ✓ **Standards Database:** Connected (AIAG-VDA, ISO 26262, MIL-STD-882 available) Root cause validation will be offered at each "Why" iteration to validate against documented failure patterns. Use `/lookup-standard [query]` for manual queries. ===============================================================================
When Unavailable:
=============================================================================== 5 WHYS ROOT CAUSE ANALYSIS SESSION =============================================================================== ⚠️ **Standards Database:** Unavailable 5 Whys analysis will proceed using standard iterative questioning methodology. Root cause validation available from embedded reference data: - ✓ 5M root cause categories (Man, Machine, Material, Method, Measurement) - ✓ Systematic vs. random failure patterns Not available without standards database: - ✗ Industry-specific failure pattern catalogs - ✗ Detailed root cause validation from AIAG-VDA, ISO 26262 To enable standards integration, ensure knowledge-mcp is configured. ===============================================================================
Important: Display status banner ONCE at session start. Do NOT repeat at each Why iteration.
5 Whys Root Cause Analysis
Conduct rigorous 5 Whys analysis using a structured, Q&A-based approach with built-in quality validation and scoring.
Overview
The 5 Whys is an iterative interrogative technique for exploring cause-and-effect relationships. The goal is to determine the root cause by repeatedly asking "Why?" until reaching a fundamental, actionable cause.
Key Principle: The number "5" is a guideline, not a rule. Continue asking until reaching a cause that, if addressed, prevents recurrence.
Workflow
Phase 1: Problem Definition
Before asking any "Why" questions, establish a clear problem statement.
Check for inherited context from Problem Definition skill:
If Problem Definition context available (from prior skill invocation in this session):
=============================================================================== 5 WHYS ROOT CAUSE ANALYSIS =============================================================================== ✓ **Inherited Context** (from Problem Definition) Problem Statement: Connector housing P/N 12345-A, Rev C exhibited cracked locking tabs (crack length 3mm) at final assembly station 3 during torque verification, affecting 12 of 400 units (3%), detected by visual inspection. Severity: 7 (AIAG-VDA FMEA Handbook (2019), Table 5.1) - Product inoperable, loss of primary function - Customer very dissatisfied [Expandable] Full 5W2H + IS/IS NOT analysis ▼ | Element | IS | IS NOT | |---------|----|----- ---| | What (Object) | Connector housing P/N 12345-A, Rev C | Other connector types | | What (Defect) | Cracked locking tab, 3mm length | Fully severed | | Where | Final assembly station 3 | Stations 1, 2 | | When | Week 12 production | Prior weeks | | How Much | 12 of 400 units (3%) | All units | =============================================================================== Proceeding to iterative Why analysis with inherited severity context...
If Problem Definition context NOT available:
Display recommendation with options:
=============================================================================== 5 WHYS ROOT CAUSE ANALYSIS =============================================================================== ℹ️ **Recommendation:** Run `/problem-definition` first No problem definition context found. For effective root cause analysis, I recommend establishing a clear, bounded problem statement first using `/problem-definition`. This provides: - Structured 5W2H + IS/IS NOT analysis - Severity classification (flows to FMEA and corrective action prioritization) - Problem scope boundaries (what IS and IS NOT affected) - Consistent context for root cause validation Options: 1. Run `/problem-definition` first (recommended for formal RCCA/8D investigations) 2. Continue 5 Whys standalone (I'll elicit basic problem statement below) Your choice:
If user chooses standalone, elicit minimal problem context:
Collect from user:
- •What is the specific problem or deviation observed?
- •When was it first observed? When does it occur?
- •Where does it occur (location, process step, equipment)?
- •What is the magnitude/extent (how many, how much, how often)?
- •What is the expected vs. actual state?
Quality Gate: Problem statement must be:
- •Specific and measurable (not vague)
- •Describing a deviation from expected performance
- •Free of assumed causes or solutions
- •Observable and verifiable
Phase 2: Team & Evidence Gathering
Collect from user:
- •Who has direct knowledge of this problem/process?
- •What data, logs, or evidence is available?
- •Has this problem occurred before? What was done?
Phase 3: Iterative Why Analysis
For each "Why" iteration:
- •Ask: "Why did [previous answer/problem] occur?"
- •Record: Document the answer verbatim
- •Validate:
- •Is this answer based on fact/evidence or assumption?
- •Does this answer logically follow from the previous statement?
- •Could there be multiple causes? (If yes, branch the analysis)
Optional Root Cause Validation (Standards Check)
After recording the "Why" answer, offer:
Would you like me to validate this proposed cause against documented root cause patterns from industry standards (AIAG-VDA, ISO 26262)?
This can:
- •
Confirm if this matches known failure mechanisms
- •
Suggest related causes or contributing factors
- •
Identify if this is a symptom vs. true root cause
- •
Provide confidence level: High/Medium/Low
- •
Yes: Query standards for root cause patterns matching "[answer]"
- •
No: Continue to next "Why" iteration
Your choice:
Query behavior:
- •If user says yes: Execute
knowledge_searchwith query "root cause pattern [answer from Why] failure mechanism common causes", filter by domain="rcca" or "fmea" - •If user says no: Continue, but still offer at next iteration (different causes may benefit from validation)
- •If MCP unavailable: Skip this prompt entirely (banner already warned user)
- •If user declines 3+ times consecutively: "I'll stop offering validation. Use
/lookup-standardif you want to validate a specific cause."
Result presentation (if queried):
High confidence match:
✓ High confidence match
This matches documented pattern: "Inadequate process control leading to variation" (AIAG-VDA FMEA Handbook (2019), Section 4.3.2)
Common related causes from standards:
- •Lack of statistical process control
- •Inadequate inspection frequency
- •Process capability (Cpk) below 1.33
This is a recognized root cause pattern. Consider if any related factors apply.
Medium confidence match:
⚠️ Medium confidence match
Partial match to documented patterns in ISO 26262-9 Section 8.4.3:
- •Systematic failures in sensor calibration
- •Environmental stress factors
Consider these related factors. You may want to explore another "Why" level.
Low confidence / No match:
ℹ️ Low confidence match
No exact match found for "[answer]" in documented root cause patterns.
This could indicate:
- •Novel root cause (not previously documented in standards)
- •Opportunity to explore another "Why" level
- •Need to refine the causal statement
Recommendations:
- •Consider another Why level or alternative cause paths
- •Search related terms: [suggested related queries based on answer]
- •Continue with this cause if supported by strong evidence/expertise
- •Test: Read the chain backward: "Therefore..." - does it make logical sense?
Stopping Criteria - Stop when:
- •Further "Why" produces no meaningful answer
- •You've reached a process/system issue (not a person)
- •Addressing this cause would plausibly prevent recurrence
- •The cause is within your control to address
- •Standards validation shows high confidence (recognized root cause pattern)
Continue if:
- •Answer is still a symptom, not a root cause
- •Answer blames a person rather than a process
- •Answer is "it's always been that way" or similar deflection
- •Standards validation shows low confidence (suggests deeper investigation needed)
Phase 4: Root Cause Verification
Apply these verification tests to the identified root cause:
- •Reversal Test: Read the chain forward with "therefore" - does each link hold?
- •Prevention Test: If we fix this cause, would the problem be prevented?
- •Recurrence Test: Has this cause produced similar problems before?
- •Control Test: Is this cause within our ability to address?
- •Evidence Test: Is this cause supported by data, not just opinion?
Phase 5: Countermeasure Development
For each verified root cause, develop countermeasures using the 5 Hows:
- •How will we fix this? (immediate action)
- •How will we implement it? (plan)
- •How will we verify it works? (validation)
- •How will we standardize it? (documentation/training)
- •How will we sustain it? (monitoring/audits)
Phase 6: Documentation & Report
Generate the final analysis report using: python scripts/generate_report.py
Quality Scoring
Each analysis is scored on six dimensions (see references/quality-rubric.md):
| Dimension | Weight | Description |
|---|---|---|
| Problem Definition | 15% | Clarity, specificity, measurability |
| Causal Chain Logic | 25% | Each link is logical and verified |
| Evidence Basis | 20% | Answers supported by facts, not assumptions |
| Root Cause Depth | 20% | Reached process/system level, not symptoms |
| Actionability | 10% | Root cause is controllable and addressable |
| Countermeasures | 10% | Specific, assigned, measurable actions |
Scoring Scale: Each dimension rated 1-5 (Inadequate to Excellent)
- •Overall Score: Weighted average × 20 = 0-100 points
- •Passing Threshold: 70 points minimum
Run python scripts/score_analysis.py with analysis data to calculate scores.
Common Pitfalls
See references/common-pitfalls.md for:
- •Stopping too early (at symptoms)
- •Blaming people instead of processes
- •Accepting assumptions as facts
- •Single-track thinking on multi-cause problems
- •Failing to validate the causal chain
Examples
See references/examples.md for worked examples including:
- •Manufacturing equipment failure
- •Software deployment failure
- •Customer complaint investigation
- •Process quality deviation
Integration with Other Tools
- •Fishbone Diagram: Use to brainstorm potential causes before 5 Whys
- •Pareto Analysis: Use to prioritize which problems to analyze
- •8D Process: 5 Whys fits within D4 (Root Cause Analysis)
- •A3 Report: Include 5 Whys in the root cause section
Session Conduct Guidelines
- •Facilitate, don't lead: Ask questions without suggesting answers
- •Document everything: Record exact wording of each answer
- •Challenge assumptions: Ask "How do we know this?"
- •Stay process-focused: Redirect person-blame to process gaps
- •Allow branching: Multiple valid answers create parallel chains
- •Verify with evidence: "Show me" is better than "tell me"
Manual Commands
/lookup-standard
Query the knowledge base for RCCA-related standards information at any point in 5 Whys analysis.
Syntax: /lookup-standard [natural language query]
Examples:
- •
/lookup-standard common root causes for sensor failures automotive systems - •
/lookup-standard systematic failures ISO 26262 definition examples - •
/lookup-standard how deep should 5 Whys analysis go stopping criteria - •
/lookup-standard validation tests for root cause analysis AIAG-VDA - •
/lookup-standard difference between symptom and root cause - •
/lookup-standard 5M Man Machine Material Method Measurement root causes - •
/lookup-standard process capability Cpk root cause manufacturing
Response Format:
## Standards Lookup: [query] ### Result 1 (92% relevant) **Source:** AIAG-VDA FMEA Handbook (2019), Section 4.3.2 [Content excerpt with relevant context] ### Result 2 (88% relevant) **Source:** ISO 26262-9:2018, Section 8.4.3 [Content excerpt with relevant context] --- Showing 3 of 7 results. Say "show more" for additional results.
When to Use:
- •Validating proposed root causes against industry-documented patterns
- •Understanding systematic vs. random failure definitions
- •Checking best practices for 5 Whys depth and stopping criteria
- •Finding example root cause analyses from standards
- •Investigating unfamiliar failure mechanisms
- •Strengthening root cause analysis with standards evidence (regulatory context)
No Results Response:
## Standards Lookup: [query] No direct matches found for "[query]". Did you mean: - "root cause pattern process control" - "common failure modes manufacturing" - "5M root cause categories" Try refining with specific standard names (AIAG-VDA, ISO 26262, MIL-STD) or broader terms.
Availability: Requires knowledge-mcp connection. If unavailable:
Standards database not available. Use embedded reference data in
references/root-cause-patterns.md.