A Model for Multi-Criteria Ranking of Sub-Transmission Power Transformer Maintenance Strategies – An Application of Delphi Process

This paper presents the practical expertise of researchers who utilized the Delphi process technique to achieve consensus among experts on sub-transmission power transformer maintenance strategies. The study employed the average consensus approach to derive a final framework with criteria for evaluation categorized under costs, added value, reliability, quality, safety, and technical aspects. The experts from a South African power system utility reached a consensus on the selected criteria from literature and additional factors proposed during two rounds of Delphi discussions. This study will assist those interested in exploring the Delphi process for decision-making, especially for selecting maintenance strategies in the power system.