event-based

Short definition from Wiktionary

Adjective

1. 1
   Synonym of event-driven.
2. 2
   Taken only when sexual activity creates a risk; on demand.
3. 3
   Pertaining to exposure (to toxic substances, radiation, etc.) that results from a (usually accidental) event, as opposed to chronic or regularly-occurring exposure.
4. 4
   Pertaining to training that involves simulated situations as opposed to drill in specific skills.