In the rapidly changing information environment, libraries have to demonstrate that their services have relevance, value, and impact for stakeholders and customers. To deliver effective and high quality services, libraries have to assess their performance from the customer point of view. Moving to an assessment framework will be more successful if staff and leaders understand what is involved in organizational culture change. This paper describes the new paradigm of building a culture of assessment, and places it in the framework of organizational culture change, utilizing a learning organization and systems thinking approach. (Contains 41 notes.)