There are a few threads about the relevance of the Cobol programming language on this forum, e.g. this thread links to a collection of them. What I am interested in here is a frequently repeated claim based on a study by Gartner from 1997: that there were around 200 billion lines of code in active use at that time!
I would like to ask some questions to verify or falsify a couple of related points. My goal is to understand if this statement has any truth to it or if it is totally unrealistic.
I apologize in advance for being a little verbose in presenting my line of thought and my own opinion on the things I am not sure about, but I think it might help to put things in context and thus highlight any wrong assumptions and conclusions I have made.
Sometimes, the "200 billion lines" number is accompanied by the added claim that this corresponded to 80% of all programming code in any language in active use. Other times, the 80% merely refer to so-called "business code" (or some other vague phrase hinting that the reader is not to count mainstream software, embedded systems or anything else where Cobol is practically non-existent). In the following I assume that the code does not include double-counting of multiple installations of the same software (since that is cheating!).
In particular in the time prior to the y2k problem, it has been noted that a lot of Cobol code is already 20 to 30 years old. That would mean it was written in the late 60ies and 70ies. At that time, the market leader was IBM with the IBM/370 mainframe. IBM has put up a historical announcement on his website quoting prices, configuration and availability. Accordin