Good news: it's easy to model
If you want to specify that
Job A produces
Report B, you could specify some kind of "covariance" using for example UML subsetting or redefginition:
You could also use association specialization, which is the better approach imho (yes! an association can inherit from another association, even if this is not well known!):
I used simple associations instead of composition, as I assume that reports shall survive the jobs that created them. You'll find more explanations about the suggested alternatives in this fascinating research paper. You may also see some practical illustrations in this question on SO (it's about association classes, but the arguments apply as well for associations in general).
Bad news: it's difficult to implement nicely
Unfortunately, once you have specified the rule in your UML model, you'll have some serious challenges for the implementation: Many languages do not support covariance.
Even worse, in the kind of covariance you have, there's no way to deduce covariance of
Report A from
Job A except the name of the classes. How would this work if you'd opted for
Job A with
Report 1? So unless you can find some construct with generics (e.g.
Job<Report X>) you might be obliged to use some ugly casting.
Some more thoughts about the design
A first question that comes to my mind is whether it is a good idea that the
Report X has also the responsibility to drive the workflow to check and validate it.
A second point to raise, is that a report is a report. Instead of an abstract
Report that is specialized, you could instead prefer composition over inheritance. In this case, every
Job would produce a
Report, but each report would itself be composed on different (eventually several) contents/components:
This will make a much more uniform handling of the reports and will simplify the design. If deemed useful, you could consider a GoF builder pattern in each
Job to assemble the reports and their component. But it is not certain imho that you'll really need the sophistication of this pattern.