If you want, we will start from the beginning ! ie, determine the data needed to the computer system in order to provide the desired data by users of the system and give there the means to express their needs.

I would quote a foreword from J.D WARNIER from his book L.D.R (Users Guide of the computer system) .

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"Many difficulties concerning the establishment of a truly satisfying the IT business needs, come from what one does not know to ask problems. It does not have the language that allow to know oneself, what we want exactly, and then to expose to others intelligibly. "

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L.D.R meets two main objectives :

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1) Make available to users and IT an expressing language of needs clear and precise that not allow any personal interpretation.

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2) Identify the primary data that must be stored in the system to obtain the desired data (required outputs (SD)).

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If we refer to the diagram of the computer system that we have seen, we will organize the system output data , and discover the primary data (*) necessary to obtain them.

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Beautiful program NO ?

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Then click

(*) There are two types of data in the system, first said "primary data" updated by the system input data, and data called "secondary data" created and updated from internal movements, obtained from the system primary data.
 

 

 

 

 

 

 

 

 

This is first, and foremost the primary data

which interest to us!

Spread the word !

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