Clarifying the objective is part of the case, especially when the prompt is broad. Ask what outcome the client actually cares about, what success looks like, and whether there are important constraints.

If the interviewer keeps the objective broad, build the structure around the major ways the business could improve and state the assumptions you are making. You can refine the structure as the case reveals more information.

The key is to avoid pretending a vague objective is precise. A strong candidate makes the ambiguity explicit and creates a workable problem definition. If useful, this guide on case structure vs. case framework gives more detail.