Birgitta Hellmark Lindgren has published "Sustainable Open Access Publishing: Preconditions, Dialog, and Continuous Adaptation: The Stockholm University Press Case" in the Journal of Electronic Publishing..
Here's an excerpt:
Given the demand for open access publishing in the context of expensive article processing charges and acquisition costs scholarly publishing needs to be transformed. I believe that university libraries are in a good position to contribute to this change. I begin with describing what Stockholm University Press is, what we do and how. I continue with describing why we do it and for whom. I conclude by pointing out some lessons learned.