Automate a transition using a custom fields value?

[Angel Casas]

Hello,Is there a way to automate a transition using a comparison of a custom number fields value? My goal is to to edit a custom issue that has a hidden field called Working Hours it's default value is 0. The user creates the issue and the agent edits that field so when the issue is edited and updated the automation would take place and decide: IF Working Hours > 40 then go to a management approval transition Else if Working Hours <= 40 it goes to a In Progress transition. 

[Gaston Valente]

Angel,

you can achieve this with a custom listener that listens the issue updated event 

This can be implemented with script runner or a similar plugin , there a lot of code samples

[Mikael Sandberg]

You need an app to do it. I use ScriptRunner to do just that, but I bet Power Scripts would work too. ScriptRunner has a built in listener that can fast forward an issue if the condition is met.