Dear Narish,
regarding the first three points
- They are using third party time system for capturing (assume: detailed clock in and out are recorded)
- The contract labour can even work for 16 hours a day
- The shift for the next day will be decided the previous day
I suggest doing one workscedule with the main shift (morning shift for example) and the other shifts created as daily workschedules.
let the shift assignments are done by dynamic assignments based on clock in (time management with clock entry or through substittion from infotype 2003