it would be great when you would realy be able to plan the shifts and so on for your technicans in the workplanner. Then you always can see how many technicans you have for the night shift and so an. Perhaps it is possible to realize it with a algorithem system e.g.
5 Days Night shift onde free day, 5 Days late shif one freeday 5 days early shift and so an and then use this algorithem for a whole year.