Libraries and librarians are under more pressure to justify their existence as value to their company/community/school. The September 2005 MLA News (pg. 10) has a list of various web sites that can help you determine and prove how much you and your library is worth to those who have the purse strings.

I found two listed sites to be particularly helpful and interesting.
Measuring Your Impact: Using Evaluation to Demonstrate Value http://www.nnlm.gov/evaluation/hospital_eval/
The course materials from a workshop include information on methods and tools for assessment, evaluation planning, creating logic models, data collection, data analysis and reporting.

Practical Tips to Help You Prove Your Value
http://www.infotoday.com/mls/may02/kassel.htm
This article covers guidelines and tips for creating, explaining, and communicating the value of the library and librarians.

Unfortunately three studies on the value of hospital libraries http://www.hls.mlanet.org/Management/hls_rochester.htm
(listed in the MLA News as a resource) are fairly old (1992, 1987, 1994). I don't mean to take anything away from these great studies, but online access and wireless technology have completely changed the playing field, so articles on The contribution of hospital library information services to clinical care (1987) and on the Effect of online literature searching on length of stay and patient care costs (1994) are not as helpful any more.

Just from casually watching my email I have noticed a greater amount of medical librarians who are in hospitals that are working with the Studer Group (or similar consulting entities) to provide "Service Excellence." These librarians are now being asked to create quantifiable performance initiatives to show how they/the library are serving hospital's mission of providing excellent service. Great in theory, but just from reading the emails it seems Studerized librarians are having a hard time developing these performance initiatives.

This leads to me to wonder. All of the resources we librarians have used to prove our value have all been based on what he have already done. For example, we helped reduce hospital costs
by reducing the library's interlibrary loan expenses by 10% through more library cooperative agreements. Was that a goal of ours before the beginning of the year? Or did that simply happen and we submitted it to our administrators as an example of the library's contribution to helping the bottom line? If there was a goal to reduce expenditures such as interlibrary loans, did we have a target and were we evaluated on whether we hit that target?
It seems what we need is more information on proving our potential value and how can we hit those target goals to realize our true value the organization.

As far as I know libraries have never been asked to increase circulation by X%, increase literature searches by X%, increase home page activity by X%. We have all looked at everything at the end of the year and said this what we have done see how we are a valuable. We haven't been asked set quantifiable goals for our services to become a more valuable asset to our organization.