From a customers perspective there are often many processes to purchase.
In the background there are a number of hidden processes such as card clearance, stock level check, postcode check, delivery time check, driver availability.
I mapped out the user journeys and combined them, with the backend calls to produce a complete Service Design.
Currys/PC World wanted to synchronise the purchase, credit clearance, warehouse stock and delivery to hold minimal stock at each warehouse and to maximise User Experience.