The Objectives and Priorities for the Azorean Dairy Farmers’ Decisions - The Agricultural Economics of the 21st Century - page 138

extreme point to another. This method uses a subroutine that allows to prove
(or not) the effectiveness of each extreme point.
The MP is hybrid between GP and MOP, which minimizes the deviation vari-
ables with a vector such as vector optimization (MOP). It brings together the idea of
“meeting” of the GP and the demand for efficient solutions of MOP. It is classified
as an interactive method, because it seeks interactively the goals or aspiration levels
of the decision center (Silva 2001 ).
When possible solutions and the efficient set are found, it is necessary to
determine the ideal solution, that is, the solution that is closest to the ideal point.
There are basically two techniques for the election of the ideal solution within the
efficient set: CP and Interactive Techniques.
The CP proposes to reduce the efficient set based on the notion of distance
between (possible) solutions and the ideal solution, through discrete or continuous
approach. This ideal is a utopian solution but it is also a reference point for the
decision maker.
The interactive methods have the advantage of the decision maker intervention,
which progressively defines his preferences. The analyst is the intermediary
between the model and decision center, that is, the first calculates and the second
decides, so there is an interaction between the decision maker and the model. There
are various interactive techniques such as STEM and Zionts and Wallenius
Methods. Other interactive methods can be found in Silva ( 2001 ).
The Multi-Attribute decision techniques are intended to select the options from
among a set of predetermined solutions (discrete set of alternatives) through a
cardinal utility function, which is a mathematical expression able to order the
preferences among different alternatives. To do so, for each attribute value a
corresponding function is determined. This system allows to distinguish the three
methodologies that are identified in Fig. 10.1 , based on discrete variables.
In the Interactive Local Judgement Approach, the process of preferences model-
ing is based on the dialogue between the analyst and the decision maker. With the
calculation process, the analyst must submit an alternative to decision maker that he
should enjoy. This cycle of dialogue and calculation ends when the decision maker
is satisfied with an alternative that he considers to be the best.
When the preferences modeling is done by a function construction that aggre-
gates multiple criteria is referred as Single Criterion of Synthesis Approach. This
technique starts from a discrete number of alternatives and accept certain assump-
tions about the preferences of the decision maker, being possible to establish the
utility function.
Finally, the Subordination Synthesis Approach assumes that preferences are
modeled by a binary relation construction, called a subordination relationship, in
order to the comparison, indifference, or preference of one of the two alternatives.