How do i get process instance errors in appian

Question

Hi 
 My requirement is to avoid mail alerts when process instance's fails with out changing existing process model designing. 
 we thought of maintaining process instance information along with errors in database, 
 Do we have any option in Appian to get process instance information along with errors like any log files or any reports

Mike Schmitt · Answer

My personal best practice these days is to set ALL process models to "send alerts to" a custom expression pointing to an expression rule that takes in the PM ID and the Initiator as parameters. 
 In most cases this expression rule just returns the Appian Admins group. But just recently I had a case where I was able to have the rule check whether the PM ID was one particular process model that was erroring a lot (with a known, low-priority error) and instead direct the notifications to a group containing just me. And it was very easy to do, only requiring an update to that expression rule (though at first I tried to make it return a direct email address, which didn't work). 
 The only downside to this is that you need to have set up process models to do this in advance, versus hardcoding the alerts to go to a particular group (or even a constant containing a group, like most process models in my system were originally configured to do). Though if it's only a particular PM you're worried about at first, then it's fairly easy to change just that PM and deploy it. I'm not quite clear on your use case though.