Human Interactivity is a Huge Problem for BPM

I came across this post on the Action Blog that discusses how the human factor and human interaction is a big problem for business process management. Ayal Steiner explains how human work is:

• Dynamic
• Tacit
• Ad hoc
• Crossins boundaries and silos
• Saturated with peer to peer interaction

Workflow that involves a human element does not fit into this rigid process. Does anyone have an examples of how they have gotten around this?