The medium model has two Access Services Manager I positions while the small library model has only one Access Services Manager I and the large library model has only one Access Services Manager II. What is the thinking behind the difference?

The difference is number of FTE supervised. In the model, the medium-sized library has two Access Services Manager Is, both of whom manage a smaller number of FTE than an Access Services Manager II. The ASM II could potentially manage twice as many FTE because this is a more advanced management position. Please remember that the sample staffing model org charts we provided are intended to be examples, and not a definitive staffing models for every library in our system. It's possible a medium-sized library could have 2 ASM Is, or they could have an ASM II, depending on number of direct reports, positions available, or other variables.