how to calulate utilization?, and Lunch hour utilization?

During lunch hour, there is $1$ check in staff, $1$ vital & EKG Staff, $2$ RNs$,4$ MDs$,2$ blood work staff, and $1$ check out staff. Very confused on how to calculate utilization. Based on the case study, The charge nurse was also responsible for managing the lunch hour. In theory, the charge nurse would give providers half$-$hour lunch breaks that corresponded with ebbs in patient arrivals, but this alignment proved very difficult. Often, the charge nurse would send providers to lunch when the clinic seemed quiet, only to have multiple new patients walk through the door just as they left. The system basically came down to staggering the lunch breaks and $$crossing fingers$$ that patients wouldn$$t build up in the waiting room while providers were out. As a result, during the $12$:$00$pm to $2$:$00$pm lunch period, there was typically only one front desk attendant, one vital$/$EKG tech, two RNs$,$ four MDs$,$ and two blood draw techs on duty. Even outside of lunch breaks, PATA ran very unevenly. Sometimes multiple providers were ready and waiting, other times a patient might have to wait for an hour before they were seen.