question

Here's some ideas that may help you get started. I haven't looked at your model, because I'm having trouble installing HC 5.3 on my computer, but maybe one of these will be helpful:

Setting Up the Optimizer

To set up the Optimizer, you first set up the Experimenter. The Optimizer and Experimenter share the list of variables. In addition, the Optimizer requires Performance Measures. Each Performance Measure is a function that runs at the end of a replication. It sounds like you'd need a Performance Measure that returns the throughput of your model. You might also need one to measure the cost of your staff (maybe $3000 for nurses and $7000 for doctors or something, just to make it so that some staff are more expensive than others).

Next, the Optimizer adds additional data to the variables, such as variable type, bounds, etc. The final required step is to specify an Objective for the optimization. Objectives are expressions based on the Performance Measures, and sometimes the variables. In your case, it sounds like you have two objectives. You want to maximize throughput, and minimize the cost of staff you are using. So be sure to add both objectives, and to select the "Pattern" option, which means to do a multi-objective search.

Interpreting the Results

The optimizer chart shows a point for each scenario it tried, on a x/y scatter plot. The default is to show the iteration number on the x axis, and the first objective's value on the y axis. But you can choose what to show on either axis. This lets you explore the results.

Hopefully that makes sense.