In its simplest form, critical path analysis assumes each activity requires one worker, but in reality this is often not true. It can be further complicated if certain activities can only be carried out by certain workers, as is the case in building projects involving skilled tradespeople. Scheduling is the task of assigning workers to the activities with the aim of completing the project with as few workers as possible, or if the number of workers is limited, completing it in the shortest possible time with the available workers.