Quality in academic libraries is a multi-dimensional construct. Quality management and quality assurance is part of measuring performance excellence. Libraries are services. To improve service quality, stakeholders' needs and expectations should be monitored and measured, shortfalls should be identified and addressed. Some basic principles are common to all measurements, but quality metrics will focus on the unique nature and factors that could affect quality of academic library services. Measuring quality includes the resources, resource delivery, the service environment, the management and staff, and the different stakeholders. In the digital environment, the academic library also moves from collection to connection, with new demands and performance indicators. Both quantitative and qualitative measurements are required to evaluate the overall performance of the library. The ultimate goal of measurement is improving the "fitness for purpose" of the library.