There are several tasks that require a group of specially programmed robots.

 

The tasks can be named tO, tM, tC and tI. Each task takes one full day to perform.
Task tO is an operational function.
TasktM is a maintainance function

Task tO and tC must be performed every day.
Task tM must be performed Wednesday through Saturday.
Task tC must be repeated Friday, Saturday and Sunday.
Task tM must be performed by all robots on Sunday, with no other tasks being performed except Task tI.
Task tI must be completed twice by each robot any time during the week.

These robots function daily, seven days a week.

Each Robot may only be programmed to perform tO twice each week.

Each Robot may only be programmed to perform tC twice each week.

Each Robot may only be programmed to perform tM any time during the week.

Tasks tI, tC, tO should be performed consecutively. 

	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday	Sunday
Robot1	Task tO	Task tO	Task tI	Task tI	Task tC	Task tC	Task tM
Robot2	Task tI	Task tI	Task tC	Task tC	Task tO	Task tO	Task tM
Robot3	Task tC	Task tC	Task tO	Task tO	Task tI	Task tI	Task tM
Robot4					Task tC	Task tC