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A. Sepehri

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A framework for making smart, sustainable, and circular strategies quantifiable

Doctoral thesis (2026) - A. Sepehri, M. van Koningsveld, Alex Kirichek
Ports are vital nodes in global supply chains, yet their accessibility is constantly challenged by natural sedimentation processes. Maintenance dredging is essential to ensure safe and efficient navigation, but decision-making in this domain has traditionally been driven by cost and time considerations alone.

This dissertation introduces a novel framework that makes three increasingly important value dimensions - smartness, sustainability, and circularity - measurable and operational. By combining data-driven analysis, physics-based modeling, and system-oriented methods, the research translates these concepts into quantitative indicators that can support real-world decision-making.

Through applications such as analyzing seagoing-dredging interactions, quantifying emissions across dredging operations, and evaluating sediment reuse strategies, this work demonstrates how port authorities and contractors can better understand trade-offs and align their objectives. The proposed event-based approach enhances transparency and enables comparison across different operational scales.

By bridging the gap between conceptual ambitions and practical tools, this dissertation provides a foundation for more informed, efficient, and environmentally responsible port maintenance strategies. ...

Dredging equipment selection in time-emission trade-offs

Journal article (2026) - Arash Sepehri, Alex Kirichek, Marcel van den Heuvel, Martin de Geus, Mark van Koningsveld
Maintenance dredging in ports and waterways is essential to ensure safe navigation. With increasing regulatory pressure on the maritime sector to reduce exhaust emissions, both dredging contractors and port authorities are seeking effective mitigation strategies. However, accurate emission estimates for maintenance dredging activities are still limited in the literature and often rely on experiential knowledge rather than scientific methodologies. This study suggests a method for estimating emissions and comparing alternative maintenance dredging strategies by quantifying trade-offs between project duration, energy consumption, and emissions. The method integrates vessel characteristics, project specifications, and sediment properties to allow for situation-specific, realistic assessments. A discrete-event simulation is used to evaluate two alternative scenarios, offering insights into the impact of key parameters on vessel selection and overall operational efficiency. The method is demonstrated using a case study of the Port of Ramsgate (UK), where estimated results are compared with real-world data for validation. Finally, the study outlines theoretical and managerial implications and suggests directions for future research. ...
Journal article (2025) - Mohammad Houshyar, Hadi Rezaei Vandchali, Mona Koushan, Vipul Jain, Arash Sepehri
Purpose – This study aims to identify and analyse the barriers to adopting Industry 4.0 technologies in inventory systems within the retail sector. Despite the critical role of these barriers in hindering the implementation of digital technologies, there is a noticeable gap in the literature regarding analytical studies that address this issue.

Design/methodology/approach – To fill this gap, the study employs a hierarchical model to examine the interrelationship between various barriers. The model integrates joint interpretive structural modelling (ISM) and cross-impact matrix multiplication applied to classification (MICMAC) analysis. The research involves interviews with a group of expert participants from the Australian retail industry, focusing on 13 key barriers identified through a comprehensive literature review and expert input. The driving power and dependence power of each barrier are assessed and classified into four clusters.

Findings – The study identifies 13 key barriers to the adoption of Industry 4.0 technologies in retail inventory systems. Among these, four stand out as the most influential: financial constraints, lack of management, organisational inadaptability and government reluctance. Financial constraints emerge as the dominant driver, as limited profit margins restrict retailers’ ability to invest in new technologies. In contrast, skill and training requirements were found to be the least consequential, indicating that workforce limitations, while relevant, are not perceived as critical in undermining inventory system performance. These results clarify the relative influence of barriers and their role in shaping adoption outcomes.

Practical implications – The study provides exploratory insights that can help retail practitioners in Australia understand and prioritise the barriers to adopting Industry 4.0 technologies in inventory systems. By mapping the driving and dependence power of each barrier, retailers can develop more targeted strategies to address the most influential challenges. While the findings are indicative and context-specific, they offer a structured basis for reflection and strategic planning, supporting the ongoing digital transformation of inventory management in the retail sector.

Originality/value – The contribution of this research lies in its context-specific examination of barriers to Industry 4.0 adoption in Australian retail inventory systems. Although previous studies have investigated Industry 4.0 adoption across various sectors, few focus on retail inventory management and the interrelationships among barriers in this specific context. By applying interpretive structural modelling (ISM) and MICMAC analysis, the study provides a structured exploration of how barriers interact, offering preliminary insights for both researchers and practitioners rather than claiming a fully novel methodological or theoretical contribution. ...
Abstract (2025) - Arash Sepehri, Alex Kirichek, Marcel van den Heuvel, Mark van Koningsveld
The concept of circularity is used as an alternative to linear flow materials in order to protect the environment from potential damage. To determine to what extent a sediment management project contributes to circularity practices, it is necessary to quantify how much of the dredged material is maintained within the system. Hence, defining boundaries for the system and circularity indicators for dredged material plays a vital role in measuring the circularity level of a certain project [1]. This study concentrates on defining circularity indicators for sediment management projects when a certain amount of material is diminished during the pre-processing stage. Besides, the perspectives of different stakeholders (e.g. port authorities, and dredging contractors) influence the selection of strategies for circular maintenance dredging [2]. ...
Conference paper (2024) - Arash Sepehri, Alex Kirichek, Marcel van den Heuvel, Mark van Koningsveld
Abstract: Efficient port operations require minimizing turnaround time which is the total duration of a vessel's stay in the port and encompasses waiting, maneuvering, berthing, and de-berthing times. The turnaround time can be reduced by optimizing arrivals and departures, maximizing berth availability, facilitating cargo handling, and maintaining water depth. Maintenance dredging, the primary method for maintaining water depth, is used as a continuous activity to ensure the available water depth is sufficient for the navigation of commercial (seagoing, inland, barges, etc.) vessels. The continuity of maintenance dredging interferes with commercial vessels that aim to be served in terminals. Despite the cost imposed on port authorities due to these interferences, addressing this challenge in a structured way is overlooked. To fill this gap, an open-source discrete-event model is presented in this study that employs agent-based simulation to model the interaction between seagoing and maintenance dredging processes. A simple case is proposed to provide an example of how this interaction is simulated. Then, the implications and limitations of this study are discussed and the directions for future research are recommended. ...

A comprehensive framework and multi-stakeholder approach

Journal article (2024) - Arash Sepehri, Alex Kirichek, Marcel van den Heuvel, Mark van Koningsveld
Ports and waterways are key in supporting the waterborne supply chains that form the backbone of global trade. Maintaining adequate water depth is vital for accessibility and safe navigation. Port authorities and contractors are the key players in developing maintenance strategies, and they strive for a mutually beneficial compromise. Port authorities aim to optimize port performance while keeping costs and delays at acceptable levels. Contractors aim to optimize the use of equipment and execution strategies to achieve cost-effectiveness and time efficiency. While minimum cost and duration are common and simple decision criteria, there is growing societal pressure to incorporate smart, sustainable, and circular elements. However, these elements are less straightforward to interpret and there is a lack of a comprehensive framework to quantify smart, circular, and sustainable strategies. This lack of clarity presents significant challenges in balancing traditional and emerging objectives in port maintenance. Our study directly addresses this gap by providing a structured approach to decision-making that integrates these critical but complex elements. As a result, trade-offs on these important issues are harder to achieve reducing the contributions of port authorities and contractors. This study addresses this gap by applying the Frame of Reference (FoR) method to extract objectives and indicators for decision-making from both the port authorities' and contractors' perspectives. We fill in the prescribed elements of the basic FoR template through a systematic literature review (SLR), clarifying to what extent consensus exists on these topics. The SLR revealed 128 articles and identified common strategies, research methods, influential journals, and contributing countries. Projecting these findings onto the basic FoR template showed that the protection of marine ecosystems and sediment management has received considerable attention from researchers while mitigating emissions and adopting smart techniques are emerging subjects in the literature that need further investigations. As a result, this study offers theoretical and managerial insights to improve what can be achieved with smart, circular, and sustainable maintenance strategies, while identifying crucial remaining knowledge gaps. ...

Adaptive m-objective ε-constraint method

Journal article (2024) - Arash Sepehri, Erfan Babaee Tirkolaee, Vladimir Simic, Sadia Samar Ali
In the current era emphasizing sustainability and circularity, supply chain network design is a critical challenge for making reliable decisions. The optimization of facility location-allocation inventory problems (FLAIPs) holds the key to achieving dependable product delivery with reduced costs and carbon emissions. Despite the importance of these challenges, a substantial research gap exists regarding economic, reliability, and sustainability criteria for FLAIPs. This paper aims to fill this gap by introducing a multi-objective mixed-integer linear programming model, focusing on configuring a reliable sustainable supply chain network. The model addresses three key objectives: minimizing costs, minimizing emissions, and maximizing reliability. A notable contribution of this research lies in elaborating on five levels of a supply chain network catering to the delivery of multiple products across various periods. Another novelty is the simultaneous incorporation of economic, environmental, and reliability objectives in the network design—a facet rarely addressed in prior research. Results highlight that varying demand levels for each facility lead to altered trade-offs between objectives, empowering practitioners to make diverse decisions in facility location allocation. The proposed mathematical model undergoes validation through numerical examples and sensitivity analysis of parameters. The paper concludes by presenting theoretical and managerial implications, contributing valuable insights to the field of sustainable supply chains. ...
Journal article (2024) - Arash Sepehri, Alex Kirichek, Solange van der Werff, Fedor Baart, Marcel van den Heuvel, Mark van Koningsveld
Purpose: Maintenance dredging can often hinder port operations resulting in waiting times for seagoing vessels. The purpose of this paper is to investigate the dynamics between maintenance dredging activities and seagoing vessels, specifically focusing on how waiting times can be reduced. Then, the role of selecting different maintenance dredging strategies in reducing these waiting times is outlined. Methods: The study analyzes historical automatic identification system (AIS) data to identify the interaction between maintenance dredging and seagoing vessels and quantify the hindrance periods for the Mississippihaven case study in the Port of Rotterdam, the Netherlands. The trajectories of the vessels are analyzed in a simple case to show how the vessels interact and how the waiting times are quantified. The interactions are checked with the Port of Rotterdam for different port calls to ensure that maintenance dredging was the reason for these delays. Results: By analyzing the AIS data analysis of vessels in a given time window, the dredgers for maintenance work can be identified and their activities within or near the terminal can be determined. In addition, the waiting time of the seagoing vessel caused by the maintenance dredging is quantified at the terminal entrance. Conclusion: The study discusses how the maintenance dredging operations could be improved by adjusting the loading and sailing phases of maintenance dredging and provides some theoretical and managerial insights. Alternative port maintenance strategies to minimize the waiting time caused by the hindrance are also discussed. ...

A hybrid decision‑making framework for a supplier selection problem based on lean, agile, resilience, and green criteria: a case study of a pharmaceutical industry

Journal article (2024) - Morteza Sheykhizadeh, Rohollah Ghasemi, Hadi Rezaei Vandchali, Arash Sepehri, Seyed Ali Torabi
In the original publication of the article first author name has been misspelled as “Morteza Sheykhzadeh”. The correct name is “Morteza Sheykhizadeh”. The original article has been corrected. ...
Journal article (2024) - Masood Fathi, Arash Sepehri, Morteza Ghobakhloo, Mohammad Iranmanesh, Ming-Lang Tseng
Assembly-line balancing is a significant issue in production systems. Employing industrial robots as the main production resource was a milestone in developing assembly lines, and emerging Industry 4.0 led industries to build collaborative assembly lines by combining robots and human operator skills. Recently, the majority of research on assembly line balancing has contributed to addressing aspects of utilizing robots in assembly lines and how they can increase line performance. Various models and methods are developed, considering different objectives and performance indicators. Despite the increasing number of studies in this area, a thorough literature review is lacking in identifying gaps, shedding light on research directions, and facilitating future development. This study systematically reviews assembly-line balancing studies targeted at assembly lines with industrial and collaborative robots. Studies are classified based on their objectives and reviewed for their solution method, line layout, and other essential specifications. A descriptive analysis is provided to assist researchers and practitioners in linking different properties of assembly lines to the objectives and applied methodologies. The results show that most studies developed models and solution methods that focused on simultaneously optimizing more than one objective. The review reveals that minimizing the cycle time is the most popular objective, and meta-heuristic algorithms are the dominant solution approaches. It is also observed that balancing assembly lines with collaborative robots has received more attention in the last five years with the emergence of Industry 4.0. The review also highlights gaps in the related literature and provides promising insights for future research. ...
Journal article (2024) - Morteza Sheykhzadeh, Rohollah Ghasemi, Hadi Rezaei Vandchali, Arash Sepehri, Seyed Ali Torabi
Due to the outbreak of COVID-19 around the globe in the last few years, the need for pharmaceutical supply chains is felt more than before. However, increasing uncertainties along with unpredictable demand for products led to disruptions in supply chains when receiving requests from retailers. These disruptions not only affected the economic aspect of supply chains but also caused shortages in hospitals and medical centers. Therefore, it has become significant for companies to select their suppliers to avoid disruptions in the case of the severity of infections. To address this issue in practice, this paper has been conducted based on a case study to address the role of lean, agile, resilience, and green (LARG) criteria in selecting the supplier in a pharmaceutical supply chain and compare the results obtained before and after the prevalence of COVID-19. The main purpose of this study is to determine and evaluate different indicators within the LARG concept to avoid disruptions when selecting suppliers. Besides, the significance of these criteria before and after the pandemic condition is addressed. Due to addressing multiple aspects of the problem, a hybrid fuzzy multi-attribute decision-making (MADM) approach is adopted for this elaboration when the four LARG criteria are integrated with eighteen supplier selection sub-criteria. To calculate the impact of each criterion (or sub-criteria), a fuzzy best–worst method (BWM) along with an additive ratio assessment (ARAS) is employed to propose a supplier ranking for a distributor of a pharmaceutical supply chain. The developed model is novel as LARG criteria in the context of supplier selection have not been studied to address the disruptions in the pharmaceutical supply chain. This is significant because it gives insight to both retailers and suppliers to emphasize the correct criteria, especially in the pandemic or related disrupting conditions. The results demonstrated that quality, collaboration, safety stock, and environmental criteria weigh the highest before the pandemic, while just-in-time delivery, lead time, safety stock, and environmental criteria weigh the highest after the pandemic. This study demonstrates that developing a supplier selection approach that meets the demand in a short time and recommends suppliers to hold surplus inventory helps the healthcare systems better respond to the market needs. ...

Designing a reliable-sustainable supply chain network: adaptive m-objective ε-constraint method (Annals of Operations Research, (2024), 10.1007/s10479-024-05961-2)

Journal article (2024) - Arash Sepehri, Erfan Babaee Tirkolaee, Vladimir Simic, Sadia Samar Ali
Due to proofing error many corrections were overlooked by typesetter. Original article has been corrected. ...
Journal article (2023) - Salman Nazari-Shirkouhi, Sepideh Miralizadeh Jalalat, Mohamad Sadegh Sangari, Arash Sepehri, Hadi Rezaei Vandchali
Attaining sustainability objectives has received wide attention in the supplier selection and order allocation (SSOA) literature. This paper aims to investigate an SSOA problem under multiple items, multiple suppliers, multiple price levels, and multiple period using a robust-fuzzy multi-objective programming in which: (a) transportation cost, delay penalty cost, and demand are uncertain; (b) four objectives are proposed to minimize total costs and the number of defective items and to maximize environmental and social impacts; and (c) all objectives of the problem have a fuzzy membership degree that is determined by the decision-makers. A robust optimization approach is elaborated as a solution procedure to address the uncertainty of the decision variables. The significance of each objective in practice is discussed based on seven distinct scenarios that produce a specific membership degree to help practitioners make efficient decisions in selecting the suppliers and allocating the orders. Two numerical examples with different sizes are conducted to validate the mathematical model. Thereafter, the sensitivity of each scenario on objectives and total satisfaction degree is analyzed. The results of the numerical solution compare the value of four objective functions under each developed scenario to provide a trade-off insight between different objectives for practitioners. Eventually, the credibility and efficiency of the proposed solution procedure are evaluated to validate the findings. ...
Journal article (2023) - Gerben de Boer, J.P. van Halem, M. van Koningsveld, F. Baart, Arie de Niet, Luke Moth, Frank Klein Schaarsberg, A. Sepehri
In the 2015 Paris agreement, countries committed to implementing measures to reduce greenhouse gas emissions to limit global warming. For the maritime industry specifically, the International Maritime Organization (IMO) has proposed measures for energy efficiency of vessels and candidate measures regarding fuel choice and speed optimisation. This article aims to contribute to the latter by showing how logistical simulations can be used to optimise fleet operations. We will illustrate this in the form of a conceptual case using one cutter and a range of barge fleets. Running simulations with all possible fleets, we will demonstrate the value of extra energy-based alternatives to challenge the fastest, cheapest and most flexible alternatives. ...