Development of Integrated Mathematical Model Multi-Project Scheduling under Renewable and Consumable Resource Constraints in Project-Oriented Industries (Case Study: Petrochemical Industry)

Saman Hassanzadeh Rohallaei¹ Mohammad Jaberi Hafshejani²

1) Department of Industrial Engineering, Mahshahr Branch, Islamic Azad University, Mahshahr, Iran,
2) Department of Industrial Engineering, Mahshahr Branch, Islamic Azad University, Mahshahr, Iran.

IOI Code : ABGG-ABHFCB
Publication : 11th.International Conference on Researches in Science & Engineering & 8th.International Congress on Civil, Architecture and Urbanism in Asia(11icrsie.ir)
Abstract :
    The time overlap of projects and severe resource constraints in project-oriented industries have made the need to develop advanced models for multi-project scheduling under resource constraints a research necessity. This study aims to develop an integrated framework for multi-project scheduling under both renewable and consumable resource constraints within project-oriented industries, such as the petrochemical industry. In this sector, concurrent project execution combined with stringent constraints on renewable resources (human labor and machinery) and consumable resources (ethane and methanol) doubles the necessity for synchronizing activity scheduling with supply chain planning. To address this need, a Mixed-Integer Linear Programming (MILP) model was designed to simultaneously optimize activity start times, renewable resource allocation, consumable resource procurement methods, multi-period inventories, and the activation of supply modes. The model was formulated for two projects over three time periods, implemented in the GAMS environment (version 24.1.2), and solved using the CPLEX solver. The solution was achieved with a status of MIP Optimal, Tolerance in a computational time of 2.241 seconds, reaching an objective function value of 12328.5 USD, which demonstrates the high efficiency of the model in solving combinatorial scheduling-supply chain problems. The results indicate that the proposed model is capable of providing an optimal combination of multi-layer production, procurement, and scheduling decisions within a short timeframe an integration that has only been limitedly addressed in previous studies, thereby providing significant structural innovation to the present research.

Keywords : mathematical modeling multi project scheduling renewable resource constraints consumable resource constraints project oriented industries