Lane, David, "The Folding Star: A Comparative Reframing and the Extension of Validity Concepts in System Dynamics", 1995
ua435
The paper reviews ideas on validation in both mainstream OR/MS simulation and SD. A tetrahedron model derived from the former literature is adapted to SD and proposed in a new form; the Folding Star. This framework structures ideas on the elements of SD activities as well as the roles and validation measures required. Further structuring using a tabular and hierarchical format results in an interpretation of current SD validity test and the proposal of two extensions, concerning cultural and operational issues. The framework is able to demonstrate the validity aspirations of different SD activities and to indicate areas for future development in validation test. It also shows the respective strengths and weaknesses of different SD activities and leads to the proposal of a new form, Extended SD, an engagement between SD and 'soft' OR which aspires to a comprehensive notion of validity.