The Russian word reshenie (решение) is broader than any single English equivalent. In the context of systems analysis and decision theory, it is important to distinguish the following meanings:
- reshenie as a set of alternatives — the considered possibilities that have been identified in one way or another by the person making the choice;
- reshenie as decision-making — the process of searching for the most preferred alternatives, involving deliberation, investigation of a question or problem, and finding the correct answer;
- reshenie as a solution — the answer itself obtained through this search, for example one or several selected alternatives, the result of analyzing a particular problem or a mathematical task;
- reshenie as a ruling, order, or resolution — decrees, regulations, directives, orders, and acts of legislative and executive authorities, as well as judicial and other rulings.
Decision-making in a professional sense is a special type of human activity that consists of a justified selection of the best (in some sense) alternative or several preferred alternatives from the available options.
In systems analysis, operations research, and decision theory, choice (decision-making) is defined as an action over a set of alternatives that results in a subset of selected alternatives. Usually this is one option, one alternative, but not necessarily.
Choice is closely related to optimization, since the latter is nothing other than the selection of an optimal alternative. The decision-making process is the central element of both individual and collective activity.
Each choice situation can unfold in different ways:
- the evaluation of alternatives for selection can be performed using one or several criteria (vector optimization), which in turn may be either quantitative (utility being an example of a criterion) or qualitative in nature;
- the mode of choice can be one-time (single) or repeated;
- the consequences of choice can be known with certainty (choice under certainty), have a probabilistic character (choice under risk), or have an uncertain outcome (choice under uncertainty).