In an interview with Broadcast, the 73-year-old explained that the programme's stars must always try to provide something new and never become complacent about their positions in Weatherfield.
Warren commented: "The actors are constantly auditioning. Every time they give a performance, the writers will be there devouring it and seeing if there is a new direction they can take the character.
"People who give the same old performance are looking for the exit."
Warren also praised what producers have in store for next week's 50th anniversary episodes, promising that the Joinery bar explosion and tram crash will be balanced with more subtle moments of family-based drama.
He said: "We're going to give viewers a tough ride. We want it to be the most spectacular [thing] we have ever done, but equally we want it to be the most human."
Coronation Street's 50th birthday celebrations begin on Monday.