Activity Sequencing Optimization in Petroleum Projects Using Simulation Modeling

Abstract

Project management benefits from mathematical models that enhance resource allocation, scheduling, and cost efficiency while managing uncertainties. Although optimization is well-studied in construction, its use in sequencing petroleum project activities remains unexplored. This study develops an integrated simulation and optimization model to refine scheduling in refinery upgrades, minimizing project duration and addressing operational complexities. This paper presents a simulation-based optimization model designed to improve scheduling efficiency in a refinery upgrade project, where multiple tasks must be executed concurrently without extending the overall project duration. The model accounts for interdependencies among activities and resource requirements across internal and external work teams, ensuring optimal coordination and utilization. Developed using AnyLogic®, the simulation framework employs a random number generator to systematically explore task sequencing variations, leading to a refined execution strategy. The optimization results indicate a 20% reduction in the project's total duration. While resource utilization was assessed, it was not the model's primary objective. The utilization of resources has shown mixed outcomes; specific resources demonstrated an improvement of nearly 50%, yet the overall average utilization significantly decreased to just 0.12%, falling below the typical baseline of 40% observed in most resources. The model's performance and the optimization outcomes are analyzed, offering a decision-support tool for complex project management scenarios.