Q:

Assign Approver based on lookup field to separate list

I am trying to make an approval workflow run off of an approver pulled from a separate list. 
For instance I have a SharePoint list called "access" that has a lookup of a choice field from a separate list called department (which is just list of departments and a person who is approver).  
What I am trying to accomplish is to have the workflow pull the associated approver based on which department that is selected in the dropdown from the "access" form.  
What I have tried so far is setting a local variable in SP designer but I am unsure of how to work the logic to pull the associated approver when a department is selected.  
I am trying to accomplish this in SharePoint designer, but if coding through Visual Studio is the better way I can give it a shot.

A:

You would use a Set Workflow Variable action. The first thing you'd do is to define the variable in the action. Click the workflow variable link to create a new string variable. Then click the value link and then click the litle FX button.
Select the list to get the approver from in the data source drop down and set the field from source to be the approver you want to get. Then you need to set the lookup connection in the bottom section of the workflow dialog. Select the field that holds the department in the Field drop down. For the value, click the little FX button and select the field from the current list item that matches the department field in the other list. CLick OK twice and you should have set the variable up. You can then do what ever you need to with it.
I'd recomend logging it to the workflow history to verify it is working first, then proceed with the additional steps required. 

