This paper investigates the notion of heterogeneity, inspired by Latour’s work on Actor Network Theory, as a lens for understanding daily work practices in a large service delivery organization. To this end, we present and discuss the findings from an ongoing research where we unpacked how system-administrators manage and negotiate incident resolution requests as part of service delivery practices. In particular, we looked into how performance metrics, such as, service level agreements (SLAs), mediated those practices. This paper contributes to the studies of infrastructure and explores the critical synergy between quantitative and qualitative methods in support of large-scale work practice research.