I am writing a duty roster at work where the shift codes are listed in columns representing dates, and rows representing employees. I am trying to work out a simple formula to check that all shifts are covered every day(column), and also that none are duplicated. Anyone have any suggestions?

Sample roster
Name M T W T F S S
Worker A 2 6 6 8 2 6 8
Worker B 6 2 2 2 8 8 2
Worker C 8 8 8 6 6 2 6

(PS. We are approx. 70 employees, so it's a bit more complex than the sample...)

KennBerg