Let’s think about some examples of projects for which Scrum is not particularly useful.
I don’t use Scrum to make a cheese sandwich. I use a waterfall
process, following a template devised long ago: I get out two pieces of
bread, slice enough cheese for the filling, and assemble the sandwich.
I also don’t use Scrum to build a set piece for a play. Instead, I
collaborate with as many other volunteers as we can reasonably use, and
work on the piece until we have to quit for the day, or until it is
done. After one or more work sessions, we finish the piece and move on
to the next. This process is neither Scrum nor waterfall in nature, but
bears more of a (rather vague) resemblance to Kanban.
So what do these examples tell us? Basically, they say that Scrum is
much less useful when the work is thoroughly understood in advance, or
when the delivery date is not specified, and not cyclic.