During the Volleyball England level 3 coaching course, one course subject was physical assessment. In particular, we looked at how to judge the sort of work players needed to do to improve their jump and upper body power. Here is a PDF with the specific tests.
The first test is for the upper body. A progression of medicine ball throws start with the shoulders. It then adds in upper core, then mid- and lower core. Full-body effort is the final stage. We expect longer throws at each stage in the progression. You can identify weak/strong areas based on that progression (or lack thereof).
The second test is for jump vertical testing. It uses a jump from a squat position (static) and a jump from a standing position (counter move) to assess plyometric efficiency. You’re looking for the latter being about 10% higher than the former. If so, then jump gains will mainly come from strength/power training. If not, then plyo training is required. Ideally, the arms are kept at the side, so testing requires some kind of jump mat or similar type of device. One could, however, use a standard jump reach testing device as an alternative.
The last test is of lateral jumping, but with the same basic idea. You compare a players single standing broad jump, multiplied by 3, to their triple broad jump (three jumps done in a row with no pause), again looking for that 10% differential. Just watching how well a player executes the triple broad jump, in fact, will tell you a lot about where they are in terms of plyometric development and coordination.
The last part of the document is a table giving distance ranges for UK female national team athletes.