Our organization went live with admissions in Tessitura this summer & we are struggling with tracking events that are included with admission. I am curious how other museum are handling similar events.
Over a year late, but...
For any events that are included with admission, we ticket them separately. We set this up as a free, "Drop in" ticket which is non-attendance bearing, and bulk print enough for our full house. We then have staff at the venue distribute those tickets as guests enter. This allows us to ensure capacity is maintained, and have an accurate count of how many attended the event. This obviously requires staff at the venue itself.
In other cases, we also build the event as a free ticket, in a facility set up for our venue's capacity, and guests can grab a ticket from the desks when they get admission. We have found in this case that often people take tickets without having a full grasp of what it's for, or a real intention of going - we tend to have some attrition. Distributing at the venue has been more effective for us.