The coordination of maintenance work in manufacturing poses a crucial productivity factor in small and medium-sized companies (SMEs) but often seems to be rather neglected in practice as well as in much of the literature on maintenance. We shed light upon maintenance coordination work by presenting a design case study conducted in an SME over approximately two years. We took a participatory design-oriented approach, involving all roles on the shopfloor affected by maintenance work. In three major iterations during the pre-study, a release-ready prototype was developed and implemented by the users over the course of one year. The evaluation of the tool showed how a new and mostly unintended practice of information flow, error reporting, and prioritization emerged such that, for instance, foremen becoming a central node of communication, formal prioritization shifting away from higher management, and actual prioritization being done by maintainers. This paper contributes to the body of CSCW work on maintenance practice in SMEs by presenting detailed empirical findings on the coordination work of maintainers, as well as the evaluation of socio-technical interventions into maintenance practices.