Pega/PRPC is a popular rules engine and BPM tool from Pega systems that is gaining good market share among large corporations. Architects and developers build the Pega/PRPC instance while administrators and even select business analysts have the option of changing workflow rules during runtime. Infact, their motto itself is "Build for change". The goal is to "eliminate software coding" and "automate manual work" to the minimum and build complex systems at the enterprise level with features right out-of-the-box.
That's how it works in the utopian world. But in the real world, you need good developer support. So the lesser the code, the closer you are to the goal of a true BPM tool. Software coding might be reduced drastically. But you still need people with a development background using inputs from Business Analysts to make changes or add functionality. Pega Training Online is pretty expensive so they primarily target any corporation that can afford such a luxury.