Selecting resource planning metrics is not very different from selecting project management metrics. In fact, in most instances, the first is a part of the second. Thus, the same principles are often applicable. However, selecting the two type of metrics isn't quite the same. There is an overlap, but the two aren't interchangeable. The confusion usually stems from the fact that resource planning and project management aren't that far from each other. The most difficult part is that a lot depends on how one or the other is defined in your organization. There isn't one straightforward answer that would work in every scenario. It's also necessary to note that not all resource planning is done to reach the same goals. Thus, selecting the right metrics might be even trickier. There's detailed resource planning or project staffing that aims to make sure that the project in question would have enough resources with the fitting competencies. There's also high-level resource planning that aims to keep resource utilization and resource usage in check in each and every project portfolio and across all the project portfolios. Obviously, the two cannot use the same metrics.
Keeping all of that in mind, we are going to go over the most critical resource planning metrics both in the context of project management and separately.