The Employee Utilization (Operational) Report gives you a quick snapshot of how well an employee's time was utilized in a given time period.
Limitation by Design
Employee Attendance Summary and Employee Attendance Details report (under Employee Time reports, Scheduled Hours column), considers hours worked by the employee only in Shift 1. These reports do not consider the number of scheduled hours an employee records in Shift 2.
However, the Employee Utilization report (under Employee Performance reports) considers hours recorded by an employee in both, Shift 1 and in Shift 2 (in the columns Total Scheduled/Clocked In Hours # or Total Scheduled Hours).
Since the report definitions for these columns differ, you will find a discrepancy when you compare the number of scheduled hours in the Employee Attendance Summary report/Employee Attendance Details report with the Employee Utilization report. This is a limitation and is as per design.