Complaint Trend & Change Point Analysis

📊 Phase 1: Baseline Period (2012-2021)

Characteristics: Relatively stable with a notable starting spike. Mean approximately 32 complaints with moderate variability.

📈 Phase 2: Gradual Increase (2021-2023)

Pattern: Steady upward trend from 44 (2021) to 100 (2023), indicating systematic changes in complaint generation or reporting.

🚨 Phase 3: Volatility Period (2024-2025)

Critical Event: Dramatic spike to 134 complaints in 2024, followed by significant correction to 71 in 2025. High volatility suggests process instability.

📏 Statistical Process Control Analysis

Upper Control Limit (3σ)

Center Line (Mean)

Lower Control Limit (3σ)

Std. Deviation (σ)

                🎯 Key Statistical Insights
                Process Stability: The system shows multiple distinct regimes, with the 2024 spike representing a potential special cause event that has since corrected.
Trend Direction: The overall upward trend indicates a systematic increase in complaint volume over the analysis period.
Current Status: The 2025 value (71 complaints) is a significant improvement from the 2024 peak but remains well above the historical mean.

            

📋 Management Recommendations

Immediate: Investigate root causes of the 2024 spike to prevent recurrence. Analyze the drivers of the 2025 improvement to sustain gains.
Process Control: Re-evaluate control limits based on recent process changes. Implement early warning systems for values exceeding 75 complaints.
Long-term: Target complaint levels below the historical mean of 45 through systematic process improvements.