At the time of change order closure, we want to certain validation before closure of change order ticket,
1. Is it possible to ask for a document (attachment) and check weather it is attached or not
2. Closure should be done post change implementation date/time filed
3. Can check value of two attribute value on attached child ticket (incident/request)
2 and 3 must be able to accomplish using the status transition with appropriate site-defined condition.
The first will require some customization using spel and may be tricky to accomplish depending on your requirements...
users renaming the file to be attach etc...
Hope this help