## 2 Literature Review: Offshore Maintenance and Asset Management
### Design Science Research for Developing Maintenance Solutions  
DSR has emerged as a valuable methodology for developing innovative solutions in various fields, including service design [23] and project scheduling [24]. It offers a systematic approach to creating artefacts, methods, and models while bridging the gap between research and practice [25]. DSR has been applied to complex problems such as distribution system reconfiguration [26] and knowledge management systems [27]. These studies demonstrate the potential of DSR and related methodologies in addressing real-world challenges across diverse domains.  
In the context of maintenance for offshore facilities, integrating Design Science Research (DSR) with artificial intelligence technologies has enabled the development of more robust planning and optimisation systems [28]. Integrity management in marine environments represents a challenge where DSR has demonstrated its value [29]. Current research focuses on developing predictive models integrating multiple environmental and operational variables [30]. A crucial aspect in the evolution of DSR has been its ability to incorporate site-specific constraints and dynamic resource allocation [31]. The developed models consider factors such as weather conditions, accessibility, and resource availability, which are fundamental elements in the offshore context [32].  
Several studies have investigated the factors influencing offshore outsourcing decisions for application maintenance, identifying critical success factors such as cost, communication, and project management [23]. Opportunistic maintenance has been proposed as a cost-effective solution for offshore wind farms, introducing market-based opportunities [33]. Maintenance cost minimisation models for offshore wind farms have been reviewed, with some strategies reducing annual costs by up to 23% [34]. Additionally, distributed agile patterns have been developed to address the challenges in offshore development, offering guidelines for practitioners adopting agile practices in distributed environments [35]. The integration of these variables has allowed for the generation of solutions that are more closely aligned with the actual needs of the industry [36].  
Currently, research has expanded the scope of DSR by incorporating criticality analysis and risk assessment [37]. The models consider technical aspects and economic and environmental factors in decision-making [38]. This holistic approach has resulted in more effective and sustainable maintenance strategies. The current trend in developing solutions through DSR points towards creating more integrated and adaptive systems [39]. Recent research emphasises the importance of combining different technologies and methodologies to address the complexity of offshore maintenance [40]. Incorporating multi-criteria optimisation techniques and real-time data analysis redefines traditional maintenance paradigms [41].  
This literature review highlights the importance of a holistic and integrated approach to offshore asset management. Combining machine learning techniques, optimisation methods, and digital twin technologies [42] promises to transform maintenance and integrity management in offshore facilities. However, it also underscores the need for continued research to address the specific challenges of these complex and dynamic environments.