Robotic Process Automation (RPA) performs high-volume tasks such as checking invoices. However, the governance and maintenance of large-scale software robot environments can be challenging when robot servers perform automatized tasks simultaneously for customer organizations with complex programming rules, dedicated parameters, and dependencies on timetables. A multivocal literature review (MLR) was conducted to explore whether there are 1) mechanisms to improve software robot maintenance in large-scale robot environments, 2) or software robot maintenance practices for scalable RPA in organizations providing shared services, 3) or governance models for optimizing the performance of software robot maintenance, and 4) is the Center of Excellence (CoE) one of the success factors concerning large-scale robot environments. By doing this, 5) we found eleven functional requirements for the monitoring tool to support maintenance in a large-scale environment. In addition, we adapted them to the RPA monitoring tool abilities for the Finnish Government Shared Services Centre for Finance and HR (Palkeet). As a result, the eleven functional requirements and the monitoring tool abilities are adaptable for other large-scale environments to improve software robot maintenance. However, commercial monitoring tools for RPA maintenance do not fulfil functional requirements, and organizations in large-scale environments must develop their monitoring tools. Based on MLR, either in-house or outsourced CoE seems to be one of the success factors in RPA maintenance in large-scale environments.