Systems Modelling: Theory and Practice brings together some of the leading minds in the fields of Systems Modelling and Operational Research, to produce a book which addresses issues that are of both practical importance and theoretical significance. This union of the theory and practice of Systems Modelling incorporates both #hard# and #soft# aspects of Operational Research, creating a complementary approach that requires more than common sense and results in significant organizational benefits ÍNDICE: CHAPTER 1. Complementarity in systems modelling (Michael Pidd). CHAPTER 2. Insights from complexity: organisational change and systems modelling (Michael Lyons). CHAPTER 3. #Classic# OR and #soft# OR - an asymmetric complementarity (Peter Checkland and Sue Holwell). CHAPTER 4. The effectiveness of high-dependency care (Roth Kowalczyk). CHAPTER 5. Complementarity in practice (George Paterson). CHAPTER 6. The complementary use of hard and soft OR in developing tax policy (Joyce Brown and Ceri Cooper) CHAPTER 7. Mental models and learning in system dynamics practice (John Morecroft) CHAPTER 8. Using causal mapping - individual and group, traditional and new (Fran Ackermann and Colin Eden). CHAPTER 9. Use of 'soft-or' models by clients - what do they want from them? (Colin Eden and Fran Ackermann). CHAPTER 10. The status of models in defence systems engineering (Sean Price and Philip John). CHAPTER 11. Complementarity in ministry of defence or practice (Alan P Robinson, George A Pickburn and Roger A Forder). CHAPTER 12. Bringing it all together (Michael Pidd). 12.1 A personal reprise. 12.2 So, what can we learn?