Large and complex systems (such as computer networks and power transmission systems) are difficult to operate and manage. Even when good remote managing capabilities are available, emergency situations prompt “alarm avalanches” that make diagnosis more difficult. This situation has prompted the development of intelligent alarm processing systems (IAP systems). Although it has been shown that IAP systems can be highly effective, most of them fail in practice due to the maintenance burden. In fact, most IAP systems require maintenance whenever the underlying monitored system changes. This paper presents the simplification and enhancement in maintainability of IAP systems made possible by separating topological information from the knowledge base (referred to as topology rule base). We investigate this idea in the context of a power transmission system, submitting to the same maintenance operations both a topology rule base IAP system and an identical traditional production system (i.e., one without topological information and with a topology-specific rule base). Our results confirm that the topology rule base substantially curtails the effort expended for typical maintenance procedures. Additionally, field experience in debugging an IAP system is described and the quality of the final system is characterized.