Awareness of others
It is a really simple concept so often overlooked or forgotten. The naive approach to designing a workflow describes the work of the organization like a machine: person A needs to do job A, then person B does job B, then person C does job C. We automatically route work to people, and they do their job. Keep your heads down, you don't need to know anything else.
This is a naive (reductionist) oversimplification of what people do. The best way to explain is by use of an analogy to soccer. A naive process designer might describe soccer as one person taking the ball halfway down the field, then a second taking it to the end zone, and finally a third making a goal. That is kind of the view that you get from the TV camera following the ball. However, what is really happening is that while person A is bringing the ball, everyone else on the team is constantly moving and adjusting their positions in order to potentially be in a position to make a play. It is obvious that the entire team is playing all the time: if you don't have the ball, then you are preparing to receive the ball, or positioning to prevent an opponent from getting the ball.
It is similar in the office: people are considering how much work is coming their way; they are preparing to do work; they are looking to see if important work made it the rest of the way; they want to know if George is going to have the time to complete all the cases that are in process. Person A needs to know how big person B's work queue is. Person C needs to know how many things persons A and B have on their plate. Person B wants to know why it is taking so long for a particular case. And everyone needs to know if people are out sick today in order to shift responsibilities around. This is not just a management task, but something that workers do naturally every day.
In spite of the simplistic 'heads-down' model of work routed to people to do job, the real benefit of a BPM system comes when it can give awareness of where the work is, how much there, how well it is being processed, etc. In other words: Awareness.