Firewall rulebases rarely become messy all at once. They usually accumulate complexity through urgent change requests, temporary exceptions, application migrations, renamed services, and rules that were never removed after a project ended.
Good cleanup focuses on security and operational clarity. Teams should look for duplicate policies, shadowed rules, unused objects, broad source or destination definitions, excessive service groups, disabled rules with unclear history, and policy comments that no longer explain the business reason for access.
A clean rulebase is easier to troubleshoot, easier to defend during an audit, and less likely to hide dangerous access. Regular automated review gives engineers a safer starting point by highlighting the rules that deserve attention first.