Calculation based on a daily total of lost hours by employee.  Any day in which an employee works at an efficiency lower than 100% there is Employee Opportunity.

Example:

Day 1:  Aaron worked 8 productive hours for the day and was at 90% efficiency for the day.  His Employee Opportunity would be 48 minutes.

Day 2:  Aaron works for 8 hours at 103% efficiency.  There is no opportunity.  Note that no extra credit is given for being over 100% efficiency.

Total:  Opportunity for these two day is 48 minutes.