Some say that allocating the right resources is the most important part of successful project management - figuring out the right person for the right activities. However, this is also a very difficult and complex process, especially if there are many projects to be completed and being able to make the right choice will have to depend on a large number of variables.
In a way, it's almost like you're expected to be Merlin. You need to make decisions but you don't quite know how to proceed despite being faced with a chaotic mess of possibilities. You might be tempted to pull out your crystal ball, but don't despair. The solution could be simpler and more intuitive than it would seem. The magic word here: skills.