After meeting all week with our BP3 UK colleagues in Austin, I commented on twitter that planning is really a good mental exercise to do, periodically.? As we exit the week, for example, we have a good model of customer segmentation and where we can invest in sales and technology on that basis.
Mental models simplify reality to something we can readily analyze, understand, and shape.? Each model doesn't fully describe the complexity that is reality, but it describes one plane through the multiple dimensions, and gives you the intellectual tools to explain actions and plans. (As a side note:? BPMN, used properly, can help you create such mental models for business processes. )
A good model for reality simplifies and focuses your team's attention on what matters most.