The reason I do a call sheet is so that I can plan the day ahead of me, and to also let all the actors/actresses know that they are filming that day too. It also means that if anythings goes wrong on set, Its covered for by this document.
As well as a call sheet a text message will also be provided as a reminder that they are filming that day.
A call sheet works great along side a production schedule to help plan and let everyone on set know what they are doing.