# DfLSS Workshop Series - Feature 004
## Test Quality Audit and Performance Optimization

This directory contains the DfLSS (Design for Lean Six Sigma) workshop deliverables for systematic test suite optimization using data-driven methodologies.

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## 📊 Workshop Modules

### ✅ MEASURE PHASE (Complete)

**Module**: Basic Statistics, Variation Analysis, and Control Charts
**Date Completed**: 2025-12-11
**Status**: ✅ COMPLETE

**Deliverables**:
- [**Statistics & Variation Analysis**](./STATISTICS_VARIATION_ANALYSIS.md) (17KB, 498 lines)
  - Comprehensive statistical baseline
  - Control chart data (X-bar, R charts)
  - Variation source analysis (Pareto)
  - Process capability assessment

- [**Quick Reference Card**](./QUICK_REFERENCE.md)
  - Key metrics summary
  - Immediate actions
  - Improvement roadmap

**Key Findings**:
- **Process Status**: IN CONTROL (stable) but INADEQUATE capability
- **Cpk**: 0.294 (target: >1.33 for 6-sigma)
- **Variation**: HIGH (CV=113.22%, target: <30%)
- **Root Causes**: I/O (35%), network (20%), complexity (15%), sequential (10%)
- **Outliers**: 21 tests (1.78%) require investigation

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### 🔜 ANALYZE PHASE (Next)

**Module**: Root Cause Analysis, FMEA, and Design of Experiments
**Expected Completion**: TBD
**Status**: ⏳ PENDING

**Planned Deliverables**:
- Root Cause Analysis (5 Whys, Fishbone diagrams)
- FMEA (Failure Mode and Effects Analysis)
- Hypothesis validation (statistical testing)
- DOE (Design of Experiments) plan

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### 🔜 IMPROVE PHASE (Future)

**Module**: Solution Design and Implementation
**Status**: ⏳ PENDING

**Planned Deliverables**:
- Optimization strategies (mock I/O, parallelization)
- Implementation plan with timelines
- Pilot testing and validation

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### 🔜 CONTROL PHASE (Future)

**Module**: Sustaining Improvements and Continuous Monitoring
**Status**: ⏳ PENDING

**Planned Deliverables**:
- SLO monitoring dashboards
- Automated control charts
- Process documentation and handoff

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## 📁 Directory Structure

```
dflss/
├── README.md                          # This file
├── STATISTICS_VARIATION_ANALYSIS.md   # ✅ Measure Phase deliverable (17KB)
├── QUICK_REFERENCE.md                 # ✅ Quick reference card
└── (Future workshop deliverables)
```

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## 🎯 Current Baseline Metrics

| Metric | Current Value | Target | Status |
|--------|---------------|--------|--------|
| **Total Tests** | 1,178 | - | Baseline |
| **Mean Time** | 0.774ms | 0.50ms | ⚠️ -29% |
| **Std Dev** | 0.876ms | 0.20ms | ❌ -77% |
| **CV** | 113.22% | <30% | ❌ -73% |
| **Cpk** | 0.294 | >1.33 | ❌ +359% |
| **P95** | 2.27ms | 1.00ms | ⚠️ -56% |
| **P99** | 5.66ms | 2.00ms | ❌ -65% |
| **Outliers** | 1.78% | <0.27% | ❌ -85% |

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## 🚀 Immediate Actions (From Measure Phase)

1. **Profile 21 Outlier Tests** (>3σ from mean)
   - Use `cargo flamegraph` for detailed analysis
   - Identify specific I/O or network bottlenecks
   - Document findings for Analyze Phase

2. **Categorize Tests by Type**
   - Add tags: `#[unit]`, `#[integration]`, `#[e2e]`, `#[property]`
   - Separate execution profiles
   - Enable category-specific SLOs

3. **Set Up Baseline Monitoring**
   - P95/P99 tracking by category
   - Control chart automation
   - SLO dashboard creation

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## 🎓 DfLSS Principles Applied

### Measure Phase

✅ **"You cannot improve what you cannot measure"**
- Established quantitative baseline (n=1,178 tests)
- Calculated control limits (UCL, LCL, centerline)
- Validated process stability (IN CONTROL)

✅ **"Variation is the enemy of quality"**
- Identified HIGH variation (CV=113%)
- Decomposed into common vs. special causes
- Prioritized root causes using Pareto (80/20)

✅ **"Data-driven decision making"**
- Used statistical methods (mean, std dev, percentiles)
- Control charts (X-bar, R) for stability assessment
- Capability analysis (Cp, Cpk) for improvement targets

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## 📚 Supporting Resources

### Statistical Tools Used
- Descriptive statistics (mean, median, mode, std dev)
- Percentile analysis (P25, P50, P75, P90, P95, P99)
- Control charts (X-bar, R with Western Electric rules)
- Process capability indices (Cp, Cpk)
- Variation analysis (common vs. special causes)
- Pareto analysis (80/20 rule)

### Data Collection Methods
- Cargo test execution with timing
- Subgroup sampling (n=5, k=25 subgroups)
- Sequential test runs for baseline
- Outlier detection (>3σ threshold)

### Standards Applied
- 3-sigma control limits (±3σ from mean)
- Cpk >1.33 for 6-sigma capability
- CV <30% for acceptable variation
- Western Electric out-of-control rules

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## 🔗 Related Documents

- **Feature Spec**: `/Users/sac/ggen/specs/004-optimize-test-concurrency/spec.md`
- **Plan**: `/Users/sac/ggen/specs/004-optimize-test-concurrency/plan.md`
- **Tasks**: `/Users/sac/ggen/specs/004-optimize-test-concurrency/tasks.md`

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## 📊 Workshop Timeline

| Phase | Start Date | End Date | Status |
|-------|------------|----------|--------|
| **Define** | - | - | ✅ (Pre-workshop) |
| **Measure** | 2025-12-11 | 2025-12-11 | ✅ COMPLETE |
| **Analyze** | TBD | TBD | ⏳ PENDING |
| **Improve** | TBD | TBD | ⏳ PENDING |
| **Control** | TBD | TBD | ⏳ PENDING |

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## 🎯 Success Criteria

### Phase Completion Criteria

- [x] **Measure Phase**
  - [x] Statistical baseline established
  - [x] Control charts created (X-bar, R)
  - [x] Variation sources identified
  - [x] Process capability calculated
  - [x] Recommendations documented

- [ ] **Analyze Phase**
  - [ ] Root causes validated
  - [ ] FMEA completed
  - [ ] Hypotheses tested
  - [ ] DOE plan created

- [ ] **Improve Phase**
  - [ ] Solutions implemented
  - [ ] Pilot tests validated
  - [ ] Cpk >1.0 achieved

- [ ] **Control Phase**
  - [ ] Monitoring automated
  - [ ] Cpk >1.33 sustained
  - [ ] Process documented

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**Generated**: 2025-12-11
**Workshop Facilitator**: Claude (DfLSS Black Belt)
**Process Owner**: ggen Test Suite
**Current Phase**: Measure → Analyze (Next)
