When should an SLC be used versus a rule?

You do not use SLCs to the exclusion of rules or vice versa. In fact, without rules SLCs cannot alert you to anything.

SLCs cannot not generate alerts. An SLC may cause an SLC type event to be generated. That event may trigger a rule, which in turn may have an associated action that generates an alert.The question is: “Which do I need to solve my problem?”

Note: By default, IBM® Sterling Control Center Monitor comes with a number of predefined, enabled rules. Alerts may be generated simply by defining and enabling SLCs, but only because of these predefined rules. Once you understand what the predefined rules do, you may decide to disable some. Disable rather than delete them as they are not easily restored.