After recapping the three major issues that characterize a software crisis
let's see what was the evidence that there was indeed a
crisis. So what I want to discuss now is the result
of a study performed by Davis in 1990s. So in even
more recent times than the 60s and the 70s. And the
study was performed on nine software projects that were totaling a
cost around $7 million and I'm going to show you how this
projects went using this representation, this pi representation, in which I'm
going to discuss what each of the segment of the
pi represent. So let's start looking at the first one.
This is a software that was usable as delivered. Other
software was delivered, and usable, either after some changes or
after some major modifications, so within additional costs involved.
But the striking piece of information here is that the
vast majority of the software, so these two slices, were
software that was either delivered but never successfully used or
software that was not even delivered. And this corresponded
to five over the seven total million dollars for
all the projects. So clearly, this shows a pretty
grim picture for software development and its success. In short,
there was clear evidence the software was becoming to
difficult too build and that the software industry was facing
a crisis. And this is what led to the
NATO Software Engineering Conference that was held in January 1969,
which is what we can consider the birth of software engineering. And what
I'm showing here is a drawing of the proceedings for that conference. And if
you look at the class notes you can see a link to the actual
proceedings, in case you are interested in
looking at the issues that were discussed.