Formulating a model of a system should start from the question Where is the boundary, that encompasses the smallest number of components, within which the dynamic behavior under study is generated?”
Pestel was a very forceful person and quickly saw the power of system dynamics.
No plea about inadequacy of our understanding of the decision-making processes can excuse us from estimating decision making criteria. To omit a decision point is to deny its presence – a mistake of far greater magnitude than any errors in our best estimate of the process.