Access control lists (ACLs) are rule sets that govern the passing of data packets through network devices such as routers and firewalls. In order to maximize data throughput and minimize security risks, they must be adjusted. The tuning process involves the reconciliation of changed access requirements with the existing rule set, identification of vulnerabilities or performance-degrading rules, and implementation of changes. Informal approaches to this complex task often involve multitasking, a strategy that leads to an increased rate of misconfiguration. To mitigate the impact of perceived task complexity, this research proposes a structured approach to the ACL refinement process. The formalized approach is meant to reduce cognitive overload among information security analysts by sequentially ordering the steps through which an access control list is modified. This work-in-progress also describes an experiment for evaluating the artifact. If supported, it will help IT professionals better secure their infrastructure.