Difference between assignment rule and data lookup

[pranavparmar]

What is the difference between assignment rule and data lookup? Does anyone know why we have two different ways to setup assignment rules?

I am curious which one to use for the assignment rules for Incidents and Catalog Tasks for Service Requests.

1. Assignment Rules - Define an assignment rule for incidents

2. Data Lookup - Data lookup and record matching support

[Michael Fry1 · Accepted solution]

Lookup rules run onChange when the lookup values match the rule, it sets (ie) the assignment group.

Assignment rules run at   insert/update. Assignment rules can use a script to set the assignment group, where lookup rules require an exact match.

Priority is another example of lookup rules, where priority is combination of Impact & urgency.

I prefer lookup rules as it sets the assignment group before the ticket is inserted/updated.

[Les1]

I second your preference for Lookup rules due to the OnChange functionality, i wish Assignment Rules were this way.

We have Assignment group as a mandatory field for ticket submission, so can't make use of Assignment Rules as the field must be populated prior to Insert.

Our issue with Lookup Rules is that one isn't able to override the lookup rule.  e.g. if condition is based on category but you want to change the assignment group, the lookup rule prevents that capability.

is there an easy method to have the cake and eat it too? (other than client scripts)

[JDC]

Hi Les1, 

Have you ever figured out on "having the cake and eat it too"?  I'm encountering similar issue where our assignment lookup rules(category based) dictates the assignment group value 

[marcguy]

One major difference is that data lookup rules can be defined to run in the client and on insert/update (i.e. immediately on the form before saving), this is useful to see which group is going to get a ticket and you have the chance to change it if it's been wrongly assigned.

Assignment rules run once the record is saved so you have to save the record to see which group has been assigned the ticket.