In the extremes of ultimate financial success or failure in the long term we can determine success, but that gives us something like 1 bit of data per 3-5 years per major software project. Is twitter successful? MySpace? Facebook? Was Netscape successful? Geocities? (The stock used to buy Geocities is currently worth about $2 billion dollars.) For each of those there are even more examples that are more difficult to determine. Modern software comes in a series of releases, how much can you attribute the success of a particular release to the existing code base, and how much can you attribute it to just the particular diffs for that release? It's a tricky problem with no easy answers.
In the extremes of ultimate financial success or failure in the long term we can determine success, but that gives us something like 1 bit of data per 3-5 years per major software project. Is twitter successful? MySpace? Facebook? Was Netscape successful? Geocities? (The stock used to buy Geocities is currently worth about $2 billion dollars.) For each of those there are even more examples that are more difficult to determine. Modern software comes in a series of releases, how much can you attribute the success of a particular release to the existing code base, and how much can you attribute it to just the particular diffs for that release? It's a tricky problem with no easy answers.