One of the primary motivations behind autonomic computing (AC) is the problem of administrating highly complex systems. AC seeks to solve this problem through increased automation, relieving system administrators of many burdensome activities. However, the AC strategy of managing complexity through automation runs the risk of making management harder. We performed field studies of current administrator work practices to inform the design of AC in order to ensure that it simplifies system management. In this paper, we analyze what system administrators do in terms of three important activities: rehearsal and planning, maintaining situation awareness, and managing multitasking, interruptions and diversions. We provide guidelines for constructing AC environments that support these activities.