In this report we examine the creation of staffing plans at ESOS (ATCC Stockholm). The staffing plan is the cornerstone in making the working schedule for the employees and is created with regard to the traffic flow in the Swedish airspace. In the thesis we have come up with a model in order to create and examine staffing plans at ESOS where ATCOs (Air Traffic Controllers) will handle air traffic 55 per cent of their scheduled working hours. This would be an increase from the current staffing plan where they handle traffic approximately 50 per cent of their time at work. In order to create a staffing plan with the model, data on sector opening hours was received from ESOS. This data showed how many ATCOs that were handling traffic at any point in time during September 2013. By analysing the data, we obtained information about the number of hours that needed to be scheduled and also when it was appropriate to place the hours. The result is one staffing plan which was created manually with a heuristic approach for competence group X. The staffing plan is created so that the ATCOs handle traffic 55 per cent of their working hours in a month with the traffic pattern as the one from the data. It is important to properly investigate the effects that might occur if a staffing plan with 55 per cent time in position would be implemented. The created staffing plan is good to use as evaluation when deciding if 55 per cent time in position is something to use or not.