|Wherever the truth of a claim is of particular importance, it may be expected of those who make the claim that they provide supporting evidence. To the extent that a claim is supported by a rational argument we would expect there to be deductive components to the argument. Such deductive parts can be checked by the use of formal techniques. The process of formalising an informal argument, even if it goes only so far as to render formally the propositions involved, may be beneficial in discovering any flaws in the argument. Flaws in the argument may themselves be symptomatic of deficiencies in the measures proposed to secure some important end, and their discovery may permit the proposed measures to be made more effective than they might otherwise be.||
The process thus superficially described may be dubbed the method of formal logical analysis, and you may note that this is a method in no way specific to the development of information systems, but which might equally apply to the design of a bridge, the drafting of legislation, or the formulation of philosophical theories (e.g. Modelling the Triple-Dichotomy).
Whether formal analysis is appropriate in any particular case will depend upon the importance of the propositions concerned, and the logical complexity of the arguments which are presented in their favour.
These arguments are potentially of exceedingly great complexity in the development of information systems, and for such developments there has been a great deal of research undertaken on the development of effective methods.