How to represent continuous activities in scenario diagram

[JoshWedgwood]

This has been discussed before. Please see this forum post:

Representation of Perpetual Activity in Scenario Diagram

I am modeling a robot that picks up and delivers items in a warehouse(on the moon). One of the entities is the box the item is stored in, this entinty has an activity “store and protect item”. This activity starts before the scenario and continues even after certain interactions ( the box is picked and moved with the item still in it). I understand that the vertical yellow bar shows the time of the activity, although I cannot drag it above it’s first interaction. I am not sure how to show that …

My personal recommendation is to model it using system states on the scenario diagram.

Josh