FACTA UNIVERSITATIS, SERIES: MECHANICAL ENGINEERING, cilt.23, ss.1-27, 2025 (SCI-Expanded, Scopus)
electing an independent quality control, test, and inspection firm (IQCTIF) as a strategic partner in railway wagons and locomotive manufacturing is critical for safety, compliance, and efficiency, as errors can lead to accidents, high maintenance costs, and reputational damage. Recent railway accidents in Germany, Spain, China, and Turkey highlight the risks of inadequate quality control. To mitigate these risks, multicriteria decision-making (MCDM) approaches help balance security tests, certifications, cost, impartiality, and technological infrastructure. Despite its importance, optimizing these processes through outsourcing remains an underexplored research area. This study proposes an IVq-ROFS-based CRITIC-WASPAS model to identify the most suitable strategic partners in railway manufacturing. The proposed model was preferred in this study due to its advantages, such as having an extremely flexible structure, providing results at a high level of accuracy, and allowing effective and successful management of uncertainties. According to the results, "Railway Certifications" (C2) is the most critical criterion, and TÜV SÜD is the most suitable partner for the railway manuf