Abstract

The motorbike industry in Bangladesh is experiencing rapid growth due to increasing demand and urbanization. However, recurring parts failures during the warranty period (first six months or 6,000 km) have led to higher maintenance costs and lower customer satisfaction. This study aims to optimize motorbike production and maintenance by systematically analyzing reliability issues using a modified Failure Mode and Effects Analysis (FMEA). The traditional FMEA is modified by introducing a dependency (D2) factor alongside severity (S), occurrence (O), and detection (D). Risk prioritization used the Risk Priority Number (RPN) based on a four-year failure dataset, validated by expert evaluations. Result reveals that battery failure as the highest-risk event (RPN = 2457), followed by carburetor fuel overflow, speedometer wetness, crankshaft failure, and fuel tank color degradation. Additionally, this study explored the causal relationship among the failures with system dynamics-based causal loop diagrams (CLD) and followed by fault tree analysis (FTA). Finally, implementation of kaizen-based action plan resulted in a 30% reduction in battery warranty claims and eliminated Pre-Delivery Inspection (PDI) failures. Therefore, the integration of FMEA, FTA, and Lean Kaizen strategies provides a robust, real-world solution that enhances system reliability, manufacturing efficiency, and customer satisfaction