Your not required to have a "schedule". You simply have to plan an audit program. Doesn't say you have to fill a whole year up with audits, just because everyone's been fooled into thinking that's the way to do it. Sure, it keep register auditors happy - they often have no clue that's not what's needed, either. In the meantime, internal auditors do audits and they aren't linked to any "event" in the business which management care about. You can't use anyone else's schedule because their business isn't youre business. Instead, find out what keeps your management awake at night instead and go audit that.