A Global View. 1. Making Decisions: a Difficult Problem. 2. From the Decision Making Procedure to MODDSS. B. The Elements of the Problems. 3. Actions, Criteria and Indicators. 4. Systems, Models and Indicators. 5. Modelling the Components. 6. Aggregated Models. C. Decision Making in the Full Rationality Conditions. 7. Identifying the Optimal Alternative. 8. Choosing among Infinite Alternatives. 9. Dealing with Risk and Uncertainty. 10. Planning the Management. 11. The Design Problem with sv Policies. 12. Off-line Non-Learning-Based Policies. 13. Off-line Learning Policies. 14. On-Line Policies. 15. Distribution Policies. D. Decision Making in Partial Rationality Conditions. 16. The Decision-Making process. 17. Choosing the Decision-Making Method. 18. Identifying Efficient Alternatives.19. Estimating the Effects. 20. Evaluation. 21. Comparison, Negotiations and the Final Decision. 22. Mitigation and compensation. E. MODSS. 23. Software Architecture of MODSSs. Appendices.