Auto Assign Change Type on Change Request Based on Lead Time

Workflow, Trigger - Change is Raised

Expression 1 - Work out today + 5 - Set output to date

addDays(today(‘Asia/Kolkata’),5)

Expresssion 2 - Work out if the planned start is greater than the output of expression 1

if{{change.planned_start_date_iso}} >= {{E1.result}}, ‘Normal’, ‘ Emergency’)

That will then give you the output is true or false, and you can add a condition afterwards to set type as. 

The issue you will have with doing this is IF, you have different change lifecycles, once the change is raised, it cannot “switch tracks” to another type of change. So you may find it doesn’t work the way you want  it to.