One of the key issues with 12-hour shift schedules is how to cover absences. With 8-hour shifts, one way to cover absences is to hold an employee on the previous shift over so that he or she works two consecutive shifts or 16 hours total. Another way is to split the vacant shift into two 4-hour segments, and have someone from the previous shift stay over for 4 additional hours and have someone from the following shift come in 4 hours early. It's fairly easy to cover the open shift this way, since the replacements are already at work or planning to work later that same day.
 

Unfortunately, 12-hour shifts are too long for either of these approaches. Holding someone over for a second shift means they would be working 24 hours (36 hours if they are scheduled to work the next day too). With a split shift, it means the replacements would be working 18 hours straight. Clearly this is excessive.
 

With 12-hour shifts, the only option is to find a qualified employee who is not scheduled to work the same day as the absence. Sounds simple, right? Well it's not. Supervisors can spend an inordinate amount of time trying to find volunteers. It can be tough to reach people. Candidates may have left town or they may be too busy to answer the phone. And they simply may not want to work that day. They might have made other plans or don't want to spoil a nice multi-day break.
 

This is one case in which scheduling software can be beneficial for the supervisors. You'll want a program that makes it easy to both identify eligible candidates and then to contact them. Eligibility may include things like: (1) job title, (2) skill sets, (3) work schedule, and (4) recent overtime hours (to prevent over-using someone). Contact can be by email or text message. If no one volunteers within a fixed amount of time, the supervisor can select someone to cover the open position using criteria such as reverse seniority. All of this saves the supervisor a huge amount of time, freeing them up to focus on other responsibilities.