Specification (data-processing)

In Data-processing, the specification is a model of a software. It is also the stage in software Génie which consists with to describe what the software must make. More generally a specification can also represent any dynamic system like an electronic circuit.

One distinguishes:

  • abstract specifications, for example a French text.
  • semi-formal specifications with a more precise syntax or comprising more or less standardized diagrams.
  • the formal specifications which presents a syntax and a semantics.

The specifications often form part of a method of software Génie (like UML or Merise) or of a formal Méthode.

Lastly, one also finds: “A method is a whole of concepts, language, tools”.

Let us notice that the term “methodology” is more with the mode than the term “method”. But if one sticks to the etymology, methodology is “the methods engineering”. The dictionary of Lalande says to us: “Subdivision of Logic, having for object the study a posteriori methods, and more especially usually, that of the scientific methods. Kant opposed Methodology to the whole of Logic (...)”.

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Examples

Validation of specification

When one wonders whether the formal text “said well” what one wants that he says, if he “correctly translates” the abstract request made by that which orders the software, one says that one makes validation. The validation cannot be automated.

Formal vs rigorous

That which proves makes a formal reasoning. That which specifies by saying “it is obvious that” and while jumping of the stages in its evidence, makes a rigorous reasoning. Another example: One can make a formal specification out of B. Then make a development (passage to the achievable code) rigorous.

The writing of the comments of a formal specification

The comments of a formal specification are written in natural language, but by avoiding the irregularities (source: Thesis of Y. Toussaint, Methods data-processing and linguistic for the assistance with the specification of software, Oct. 1992, U.P.S. Toulouse). But those are not always a defect!

  • noise, information nonnecessary to the moment when it is given
  • silence, concepts introduced without definition (a little like a not-declaration variable)
  • contradiction
  • on-specification: in saying too much. For example, to treat implementation whereas one did not specify the function which one wants to implement.
  • ambiguity, i.e. a statement with multiple interpretations
  • the reference ahead (is not inevitably bad!), one mentions concepts whose definition will be provided further. For example, a synopsis is made of reference ahead!

With reading

  • IEEE Guide 830
  • Guide AECMA PSC-85-16598

See too

Random links:Joseph Cali | The Lark | Theater of Patolampi | Meteor FL.53 | KH Zagłębie Sosnowiec | Hlothhere_de_Kent