Maintenance Optimization on Critical Electromechanical Equipment: A Case Study in Sasol Synfuels Catalyst Preparation Unit

International Journal of Mechanical Engineering

© 2025 by SSRG - IJME Journal

Volume 12 Issue 3

Year of Publication : 2025

Authors : Pretty Maphosa, Patrick Nziu

10.14445/23488360/IJME-V12I3P107

How to Cite?

Pretty Maphosa, Patrick Nziu, "Maintenance Optimization on Critical Electromechanical Equipment: A Case Study in Sasol Synfuels Catalyst Preparation Unit," SSRG International Journal of Mechanical Engineering, vol. 12,  no. 3, pp. 78-92, 2025. Crossref, https://doi.org/10.14445/23488360/IJME-V12I3P107

Abstract:

The challenge of optimizing maintenance strategies in industries is not a new one. It remains a relevant topic of investigation because each industry is unique in terms of its products, machinery, and operations, among other factors. Therefore, a single optimal maintenance solution cannot be universally applied across all industries. The purpose of the study was to investigate and optimize the maintenance practices used on critical electromechanical equipment in Sasol Synfuels Catalyst Preparation. Using both the Analytical Network Process (ANP) and Analytical Hierarchy Multi-Decision Approach (AHP), the analytical network and hierarchy process application and the super decision network model framework were analyzed to obtain the ideal maintenance solution for the critical electromechanical equipment within the Sasol unit. Criteria nodes such as maintenance cost, machinery availability, mean repair time, and environmental safety were chosen through a qualitative approach. The ANP and AHP approaches have different problem identification frameworks and cluster dependencies; however, it is seen that both methods portray more or less similar results, as both methods indicate that the condition-based maintenance strategy is the most weighted alternative node for optimal maintenance solution. The least weighed alternative node is corrective maintenance. Fixed-time maintenance is the second most weighed maintenance strategy, followed by the operate-to-failure strategy. For criteria nodes, it was drawn that the ANP approach resulted in the environmental safety impact being the most important criterion to consider when applying the optimal maintenance strategy in the Sasol Synfuels Catalyst preparation unit.

Keywords:

Maintenance strategy, Analytical Network Process, Analytical Hierarchy Process, Maintenance optimization, Electromechanical equipment, Petrochemical, Criteria node, Alternative node.

References:

[1] Malek Tajadod et al., “A Comparison of Multi-criteria Decision-making Approaches for Maintenance Strategy Selection,” International Journal of Strategic Decision Sciences, vol. 7, no. 3, pp. 51-54, 2016.
[CrossRef] [Google Scholar] [Publisher Link]
[2] Ling Wang, Jian Chu, and Jun Wu, “Selection of Optimum Maintenance Strategies based on a Fuzzy Analytic Hierarchy Process,” International Journal of Production Economics, vol. 107, no. 1, pp. 151-163, 2007.
[CrossRef] [Google Scholar] [Publisher Link]
[3] Maurizio Bevilacqua et al., “Development of Innovative Criticality Index for Turnaround Management in an Oil Refinery,” International Journal of Productivity and Quality Management, vol. 9, no. 4, pp. 519-543, 2012.
[CrossRef] [Google Scholar] [Publisher Link]
[4] Gregory Michael Bosco, “Practical Methods for Optimizing Equipment Maintenance Strategies Using an Analytic Hierarchy Process and Prognostic Algorithms,” Thesis, Tennessee: TRACE: Tennessee Research and Creative Exchange, pp. 1-183, 2017.
[Google Scholar] [Publisher Link]
[5] Roman Denysuik et al., “Multi-Objective Optimization of Maintenance Scheduling: Application to Slopes and Retaining Walls,” Procedia Engineering, vol. 143, pp. 666-673, 2016.
[CrossRef] [Google Scholar] [Publisher Link]
[6] “Department of Alternative Energy Development and Efficiency (DEDE),” Thailand Energy Situation, Report, Ministry of Energy, Thailand, pp. 1-41, 2009.
[Google Scholar] [Publisher Link]
[7] Gustav Fredriksson, and Hanna Larsson, “An Analysis of Maintenance Strategies and Development of a Model for Strategy Formulation- A Case Study,” Master Thesis, Sweden: Chalmers University of Technology, pp. 1-156, 2012.
[Google Scholar] [Publisher Link]
[8] Devarun Ghosh, and Sandip Roy, “A Decision-Making Framework for Process Plant Maintenance,” European Journal of Industrial Engineering, vol. 4, no. 1, pp. 78-98, 2009.
[CrossRef] [Google Scholar] [Publisher Link]
[9] Patrik Hilber, “Maintenance Optimization for Power Distribution Systems,” Ph.D. Thesis, Department of Electrical Power Engineering, KTH, Stockholm, 2008.
[Google Scholar]
[10] Fereshteh Jaderi, Zelina Z. Ibrahim, and Mohammad Reza Zahiri, “Criticality Analysis of Petrochemical Assets Using Risk-Based,” Process Safety and Environmental Protection, vol. 121, pp. 312-325, 2019.
[CrossRef] [Google Scholar] [Publisher Link]
[11] Shalu Kaushik et al., “A Review Based on Various Applications to Find a Consistent Pairwise Comparison Matrix,” Journal of Reliability and Statistical Studies, vol. 17, no. 1, pp. 45-76, 2024.
[CrossRef] [Google Scholar] [Publisher Link]
[12] Mobius Institute, “Vibration Analysis Training Manual: Version 4.1, Victoria: Mobius Institute,” 2016.
[13] Charles M.M. Ondieki, “Training Manual for ITEC 236: Terotechnology,” Faculty of Engineering and Technology, Department of Industrial and Energy Engineering, Report, Egerton University Njoro, Kenya, pp. 1-77, 2007.
[Publisher Link]
[14] Youssef Sadraoui et al., “Optimization of Quality Process Control and Preventive Maintenance Strategy: A Case Study,” Operations Research Forum, vol. 5, 2024.
[CrossRef] [Google Scholar] [Publisher Link]
[15] SASOL, Sustainable Development Report, pp. 1-56, 2012. [Online]. Available: https://www.sasol.com/sites/default/files/2022-04/Sustainable%20development%20report%20-%202012.pdf
[16] Mahmood Shafiee, and John Dalsgaard Sorensen, “Maintenance Optimization and Inspection Planning of Wind Energy Assets: Models, Methods, and Strategies,” Reliability Engineering and System Safety, vol. 192, 2019.
[CrossRef] [Google Scholar] [Publisher Link]
[17] Arash Shahin, Ehsan Pourjavad, and Hadi Shirouyehzad, “Selecting Optimum Maintenance Strategy by Analytic Network Process with a Case Study in the Mining Industry,” Productivity and Quality Management, vol. 10, no. 4, pp. 465-483, 2012. [CrossRef] [Google Scholar] [Publisher Link]
[18] E. Shayesteh, J. Yu, and P. Hilber, “Maintenance Optimization of Power Systems with Renewable Energy Sources Integrated,” Energy, vol. 149, pp. 577-586, 2018.
[CrossRef] [Google Scholar] [Publisher Link]
[19] M. Sondalini, Lifetime Reliability Solutions, 2018. [Online]. Available: www.lifetime-reliability.com/cms/faqs/reliability-improvement/faq-pragmatic-maintenance-strategy/
[20] Jureen Thor, Siew-Hong Ding, and Shahrul Kamaruddin, “Comparison of Multi-Criteria Decision-Making Methods from the Maintenance Alternative Selection Perspective,” The International Journal of Engineering and Science, vol. 2, no. 6, pp. 27-34, 2013.
[Google Scholar] [Publisher Link]
[21] Wann-Ming Wey, and Kuei-Yang Wu, “Using ANP Priorities with Goal Programming in Resource Allocation in Transportation,” Mathematical and Computer Modelling, vol. 46, no. 7-8, pp. 985-1000, 2007.
[CrossRef] [Google Scholar] [Publisher Link]