
The Concept of Collision Checks
Use
When you enter a new record, the system carries out a check to ensure that there are no existing records for that particular employee and time period.
It is not possible, for example, to enter an absence record if there is already an attendance record in the system for the same employee and time period.
Features
When you customize the system, you can determine the system reaction if time data records collide. There are four possible reactions:

System reaction:
When you enter this data for the attendance type Attendance hours, the system draws your attention to the fact that a leave record already exists for the period. The leave record is automatically delimited if you proceed to save the attendance record.
System reaction:
The system does not allow this particular constellation, as it is not logical to assign a substitution to an employee who is not at work. An error message is displayed and the system rejects the record.
System reaction:
This combination is permitted. Overtime and substitution records are not mutually exclusive. The substitution may involve the employee working different hours from normal, however. If this is the case, it may be that the new working time coincides with the period in which the employee is authorized to work overtime.
It is therefore preferable that the system draws your attention to the collision so that you can check your entries.
System reaction:
This constellation is allowed, since substitutions and absence quotas are not mutually exclusive. There is no time correlation between these two subtypes. The system therefore accepts the absence quota without drawing your attention to the existing substitution record.