Optimizing LPG Distribution Resilience: A Fuzzy-Heuristic Approach and Monte Carlo Simulation for Single-Manifold Bottleneck Mitigation in Refinery Facilities

Diaz Mondrian (Department of Industrial Engineering, Universitas Sebelas Maret, Jawa Tengah, 57126, Indonesia)
Eko Liquiddanu (Department of Industrial Engineering, Universitas Sebelas Maret, Jawa Tengah, 57126, Indonesia)

Spektrum Industri
Vol. 24 No. 2 (2026): Spektrum Industri - October 2026

Operational bottlenecks in LPG refinery distribution can arise from single-manifold constraints, creating a critical trade-off between throughput maximization and product quality assurance. Existing scheduling approaches often address vessel evacuation and blending separately, leaving a gap in integrated decision models that simultaneously consider infrastructure constraints, production fluctuations, and quality specifications. This study aims to develops an integrated simheuristic decision-support framework combining a five-tier Lexicographic Heuristic Priority Rule, Fuzzy Logic membership functions, and a Zero-Sealing mechanism to prevent off-specification products from entering distribution. The framework enables refinery managers to determine achievable throughput through a single manifold while maintaining product quality. A discrete-event simulation with hourly time steps was developed over a 31-day operational horizon using historical vessel arrival, distribution, and production data from a refinery case. Model performance was evaluated through Monte Carlo simulation under four uncertainty dimensions: maritime arrival variability, batch-size variation, pipeline degradation, and upstream feed-quality fluctuations. Sensitivity analysis was conducted to identify critical operational thresholds. Across the tested scenarios, the framework recorded no overfill incidents or quality specification violations and achieved a mean domestic gas supply of approximately 1,355 MT/day, evacuating nearly all available upstream production. Pipeline rate degradation was identified as the most sensitive parameter, affecting both throughput evacuation and quality control when capacity declined below a critical level. The findings demonstrate that evacuation capacity and quality management are structurally interdependent in single-manifold systems. The proposed framework contributes provides a quantitative decision-support tool for reducing off-specification risks and informing refinery infrastructure investment decisions.