1. Chiara Mocenni Roma, June 4-5, 2009 Dept. Information Engineering – Centre for the Study of Complex Systems – Univ. of Siena The “DITTY” DSS In the DITTY Project the DSS: accounts for the complex time-space dynamics of the ecosystems (models); evaluates alternatives according to several indicators (ecological, economic, etc.); includes multicriteria decision algorithms driven by models and end user expertise;

2. Chiara Mocenni Roma, June 4-5, 2009 Dept. Information Engineering – Centre for the Study of Complex Systems – Univ. of Siena The “DITTY” DSS The first steps for the development of the DSS was to unify the language and to define the structure.

3. Chiara Mocenni Roma, June 4-5, 2009 Dept. Information Engineering – Centre for the Study of Complex Systems – Univ. of Siena The control options are alternative actions, strategies and/or policies can be undertaken to affect the system behavior. The criteria on which the system performance led by each control option is evaluated. The objectives related to the criteria that the decision maker wants to optimize. The constraints, establishing thresholds and bounds for all the criteria in order to make the alternatives feasible or acceptable. Terminology of the DSS

4. Chiara Mocenni Roma, June 4-5, 2009 Dept. Information Engineering – Centre for the Study of Complex Systems – Univ. of Siena Structure of the DSS Control options Models Multicriteria Analysis External factors Decision Value assignments of the control options. In the DSS the values of control options are changed, often repeatedly, to reflect potential changes in environmental and internal factors (e.g., area dedicated to aquaculture). External factors

5. Chiara Mocenni Roma, June 4-5, 2009 Dept. Information Engineering – Centre for the Study of Complex Systems – Univ. of Siena Structure of the DSS Control options Multicriteria Analysis External factors Decision Exogenous inputs are inputs that are not changeable by the decision maker (e.g., weather conditions, water inflow, economic values, etc.) Models

6. Chiara Mocenni Roma, June 4-5, 2009 Dept. Information Engineering – Centre for the Study of Complex Systems – Univ. of Siena Structure of the DSS Controp options Multicriteria Analysis External factors Decision Site simulation and evaluation of indicators (correspond to decision criteria). Remark: The internal structure of this block is site-dependent… indicators Models

7. Chiara Mocenni Roma, June 4-5, 2009 Dept. Information Engineering – Centre for the Study of Complex Systems – Univ. of Siena Structure of the DSS Control options Multicriteria Analysis External factors Decision Tools supporting decision making in situations when multiple and conflicting objectives/criteria are present, and possibly both qualitative and quantitative aspects need to be considered (e.g., Analytic Hierarchy Process). Models

8. Chiara Mocenni Roma, June 4-5, 2009 Dept. Information Engineering – Centre for the Study of Complex Systems – Univ. of Siena The Analytic Hierarchy Process (AHP), [T.Saaty (1980)], is a powerful tool that may be used to make decisions when multiple and conflicting objectives/criteria are present, both qualitative and quantitative aspects of a decision need to be considered. AHP is effective in dealing with complex decision making because it reduces complex decisions to a series of pairwise comparisons.

9. Chiara Mocenni Roma, June 4-5, 2009 Dept. Information Engineering – Centre for the Study of Complex Systems – Univ. of Siena Application of the DSS to the Ditty sites