well - in principle, "Operations" transform resources (or data inputs) into desired goods, services, or results, hence creating value to recipients (mostly: customers). Two or more connected operations constitute a process, and are generally divided into four basic categories:
For each of these categories, efficiency is name of the game. This means that either the output is maximized (given certain resource inputs), or resource input needs are minimized for a desired output.
So for example for processing, operations problems can cover yield improvement problems, while for inspection, there might be the topic of automation (hence reducing input resource needs). And so on. You can draw a whole landscape of problems.
In operations cases, very often, you need to find the bottleneck that causes the respective operations problem, and then outline measures to remove this bottleneck. So this means that operations cases are, at their core, similar to profitability cases. It is a diagnostic problem which you need to address by first isolating the problem driver (the "what"), and then diving deep to understand the "why" behind the problem.