On simple baselines for domain shift in condition monitoring : a case study in bearing fault identification

Panić, Branislav (author), Pasic, Mirza (author), Nagode, Marko (author), Oman, Simon (author)

Methods for handling domain shifts in condition monitoring have proliferated, yet their evaluation often lacks rigorous baseline comparisons and systematic isolation of individual shift factors. This paper proposes a task-focused methodology that structures domain shift studies as a pipeline from data collection through task definition, dataset construction, representation, normalization, model specification, and training. Using bearing fault identification as a case study, we introduce the Relative Performance Drop (RPD) metric and conduct over 600,000 evaluations across the Case Western Reserve University and Paderborn University bearing datasets. Our results reveal that domain shift severity depends strongly on which physical factors vary: rotational speed causes substantial degradation (42.8% RPD), load and force have negligible impact, while shifts in fault type or severity suggest the task itself may require reframing rather than more sophisticated algorithms. Design choices often treated as implementation details can influence cross-domain performance as substantially as model architecture, with optimal choices reversing across collections. A difficulty taxonomy clusters domain pairs by their mean and variance of RPD, distinguishing shifts addressable by simple pipeline design, those requiring dedicated adaptation methods, and those indicating ill-posed task definitions. The accompanying open-source implementation enables application of this methodology to new collections and tasks with full reproducibility.

• Language: English
• Keywords: condition monitoring, domain shift, bearing fault identification, deep learning, baseline study, transfer learning
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2027
• Number of pages: 17 str.
• Numbering: Vol. 277, part 2, art. 113041
• PID: 20.500.12556/RUL-185103
• UDC: 62
• ISSN on article: 1879-0836
• DOI: 10.1016/j.ress.2026.113041
• COBISS.SI-ID: 285742339
• Publication date in RUL: 22.07.2026

Record is a part of a journal

• Title: Reliability engineering & systems safety
• Shortened title: Reliab. eng. syst. saf.
• Publisher: Elsevier
• ISSN: 1879-0836
• COBISS.SI-ID: 23109381

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: spremljanje stanja, sprememba domene, okvare ležajev, globoko učenje, izhodiščna študija, prenosno učenje

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0182
• Name: Razvojna vrednotenja

• Funder: Other - Other funder or multiple funders
• Funding programme: Ministry of Civil Affairs of Bosnia and Herzegovina
• Project number: 10-33-11-7357/23
• Name: Napovedovanje poškodb rotiratočih se strojnih elementov na podlagi metod strojnega učenja
• Acronym: PROROT