In the current digitalised society keeping assets secure is one of the most prominent challenges organisations face. In the ongoing arms race between attackers and defenders, software security patching is a well-recognised and effective strategy to mitigate vulnerabilities in software products. However, organisations struggle with the best practice to “patch early and often”, resulting in vulnerabilities in software being exposed for much longer than desired. Prior research indicates the socio-technical nature of this practice forms the core of delays in software patch management. Developing a deeper understanding of the decision-making of IT practitioners and what socio-technical factors play a role in this process allows organisations to address the ineffectiveness of their security patch process. The main research question in this explorative research is: What socio-technical factors influence the effectiveness and timeliness of the security patching process in organisations? This Mixed Methods research combines qualitative data from interviews with IT practitioners, with a quantitative data exploration of the meaningfulness of organisational measurements. Findings show that IT practitioners go through a funnel of decision-making that influences the decision of what to patch, and when to patch. The presence and interplay of different socio-technical factors related to four main aspects of this decision (i.e., security, applicability, operability, and availability) result in tensions and trade-offs influencing the decision space of IT. Furthermore, this study indicates the interrelations between the significance of socio-technical factors, which is reduced by certain coping strategies applied by IT practitioners. This research reveals that having some measurement in place helps to understand the existence of challenges and the working of coping strategies, therefore contributing to an understanding of socio-technical challenges. However, it also reveals several limitations to the quality of existing data and difficulties in coming to measurements that provide meaningful information, due to socio-technical factors. The main contribution of this research is a better understanding of how socio-technical factors influence the decision-making process of IT practitioners. This research is limited in the way it uses quantitative data to understand patching activity. Future research is recommended to compare the potential discrepancy between what IT practitioners state influences the effectiveness of their security patch process and what the actual patching activity of IT practitioners reveals about the effectiveness of patching. This research furthermore hypothesises that not all socio-technical factors have the same level of significance. It is recommended to investigate the possibilities of quantification of the importance of each of the socio-technical challenges identified in this explorative study.