I think I'd use a colon or a dash instead of a semicolon. It's being followed by a list, after all; but it's not wrong, just not optimal.
As for the list itself, it's not parallel enough. Parallel constructions reduce understanding effort and make things clearer to listeners and readers.
The four things in the list need to have more parallel structures, and I'd reduce them to three, putting the first and last together, and I'd use NP compounds instead of prepositional phrases, which are notoriously subject to attachment ambiguities
- interaction and allocation of processor time among processes,
- sharing and competition for resources,
- synchronisation of multiple process activities
(btw, use among, not amongst, unless you're being consciously archaic, and there's no reason to use Passive in the main clause). So the "improved" sentence would be
Concurrency encompasses a host of design issues -- interaction and allocation of processor time among processes, sharing and competition for resources, and synchronisation of multiple process activities.