What is L.C.S ?

​

For information, J. D WARNIER's first work on this subject was published in 1974 ! And the last version in 1983 !, practically 10 years of experience to refine and improve the method L.C.S.

​

The purpose of the System Building Logic is to try to answer the following question: "How to discover and organize the containers (Files for the computer scientists) of data for a computer system corresponding to a company or a defined management unit ?"

​

We are here probably faced with the major problem posed to the computer scientist, because from the organization of the data sets (or files) of his database will depend largely , the reliability and the performance of his system.

​

I think today (this is a very personal reflection given my professional experience) that the vast majority of computer systems support databases whose organization is otherwise catastrophic, at least in very bad condition (in terms of Organization of files and content of files).

​

For if, at the beginning of the creation of a system, our common sense guides us relatively well, we must admit that, over time, it degrades at a striking speed, in some cases to almost total incapacity to be able to modify this base, even to understand something there.

So let's ask the question WHY ?

​

This is certainly not the fault of the computer scientists themselves, because they do what they can with the means at their disposal, and it is not always easy to marry timing and reflection !, and then acknowledge it, We always tend to go fast to save time, unfortunately it is the reverse that we should do, go slowly to save time! But obviously it is not in human nature, especially that of computer scientists. In fact we did not have the organizational tools and mathematical laws that lead to a satisfactory result. This is why J.D. WARNIER attempts through what is called the L.C.S method (although I do not like this word very much), to give us the reasoning process and the appropriate mathematical laws.

​

Finally, before I get to the heart of the matter, I would like to point out that there are (or existed) many methods that had the same objective (MERISE, SADT, UNWTO ...... in passing) but obviously that it is a resounding failure. Again we might ask why ?

​

I believe that one of the major reasons (I can of course be mistaken) is that most of the methods proposed were not based on rigorous concepts of logic and mathematics, they were often complex and, above all,  and subject to interpretations by those who were to implement them. I remember reading many of these books and I was never go to the end, maybe I had to get out of Harvard !!!

​

It is also possible to make some criticisms about LCS, I have often hearded the following criticism, (*) "LCS is a too long a method to implement, and asking for too much documentation, one spends hours to give birth a mouse Etc ... ". It is true it is long and sometimes tedious I grant you, but how to do otherwise if you want a perfect result in logic !, but after, for technicians, who have the heavy load of implementation , it is a true happiness because they know what they do.

​

​

What is more satisfying than doing knowing what we do !

​

                                                                                                            (It's not from me but JDW)