Libraries, an important factor in today's information world, are increasingly confronted with new technologies. The use of technology challenges fundamental assumptions on which libraries have operated. The continual aspect of change brings about uncertainty, a situation libraries are not used to. They have to deal with organizational challenges such as restructuring the institutions as well as the establishment of new services for their users. In the U.S. in particular, consultants have been playing an important role in supporting libraries during this process, whereas in Europe there is no history of library consulting. Only recently some libraries, for example, the National Library of Switzerland, have begun working with consultants. A consultant was hired to assist the library in its evaluation process for an automated library system. The case study presented here reflects the consulting process from two perspectives, the client's and the consultant's view. Changes in the communication structure within the library as well as the consultant's influence in the decision making are emphasized.