The system has a set time for pick up or approximately how long it takes to prepare the order (Pick Up or Dine In). Located under "Manage Restaurant" -> "Restaurant Account Information". It's called "Default Order Ready Time"
Delivery Time is set under Delivery Settings (Manage Restaurant -> Delivery Settings)
IMPORTANT: Delivery time is always added to the pick up/dine in/default order ready time.
This makes the actual delivery time: 30 + 20 = 50 Minutes.
Orders for Pick Up or Dine In, see the ready time as 30 Minutes.
In order to adjust pick up or dine in time, you can adjust the Default Order Time settings.