Zero Flight Time
To qualify for a Zero Flight Time type rating, you need 1000 hours jet airline time. (Not sure if there's a minimum MTOW for those hours)
Once you finish in the sim, BA can send you straight to a passenger carrying aircraft for your first 'real' landing. Basically it saves the company from laying on a base training trip where you would normally have to complete 6 landings.
So ex-BMI guys with a 320 rating will save BA money compared to say an ex-RAF fast jet guy.