So let's look at each one of these items individually, starting from
the first one. And here this item has to do with how
the machine stores the information and
how the corresponding algorithm is written.
But it has no bearing in the real world. That is, in
the application domain. Therefore this. Definitely
belongs to the machine domain, and
we're going to put a one here. What about a notification of
the arrival of a message on a smart watch? This is an
event that is generated within the machine, but it has an effect,
an observable effect, in this case, in the real world as well.
Therefore, we're going to mark this as three. So this is an
event. This is something that belongs
to the intersection between the application
domain and the machine domain. So it's something that could be in
the specification. Now what about an employee that wants to organize a
meeting with a set of colleagues? This is an event that belongs
to the application domain because it is a fact that it's true
that exists. In the real world independently from the existence of a machine.
Therefore, we're going to mark this as two.
Finally, the event of a user clicking on a
link on a web page is an event that occurs in the real world but that has an
effect also within the machine and, therefore, we're
going to mark this as three, something that happens
at the intersection. between these two domains, and once
more, something that could be in a specification.