Reverse Engineering applied to Bus and Rails Spare Parts: Challenges, Methodologies and Practical Solutions

Jean Ramolivaz

Reverse Engineering applied to Bus and Rails Spare Parts: Challenges, Methodologies and Practical Solutions.

Rel. Luca Goglio. Politecnico di Torino, Corso di laurea magistrale in Automotive Engineering (Ingegneria Dell'Autoveicolo), 2026

Abstract

Public transport fleets in the bus, rail, and tram sectors are characterized by long service lives and recurring spare-parts availability issues, especially when original manufacturers reduce support or spare parts become obsolete. This thesis, developed in collaboration with VAR S.r.l. (CBM Group), investigates reverse engineering (RE) as a practical pathway to restore technical data and re-enable manufacturing of legacy parts. The work provides a structured review and application-oriented discussion of RE enablers, covering data acquisition through manual metrology, coordinate measuring machines (CMM), and 3D scanning, followed by scan-data post-processing and CAD reconstruction up to NURBS surface modelling. In parallel, the current VAR spare-parts development and validation workflow is mapped and analysed to identify bottlenecks affecting time-to-approval.

A case study on a gas spring for the North American market is used to examine the company’s validation logic based on the Part Approval Sheet (PAS), including the management of missing documentation, handling of nonconformities, and the integration of functional testing with dimensional verification to achieve production approval