I spent considerable time searching for a clear definition of either collection management or development within the NSW DEC intranet and more broadly. There were documents relating to the shared role between the Principal and the TL and the importance of libraries in general but no clear definition of the above terms.
Eventually I found a definition. Gregory (2019, pp. xiii-xiv) proposes that collection management is the term that encompasses all of the processes required to support a library of which collection development is a component. Specifically,
“Collection development is the subpart of collection management that has primarily to do with the decisions that will result in the acquisition of materials”.
The biggest difference between Gregory’s definition and others is that there are clear definitions for both terms and how they interrelate as opposed to preferring on term over the other. Her definition of Collection Management states,
“Collection Management may best be defined as the process of information gathering, communication, coordination, policy formulation, evaluation and planning that results in decisions about the acquisition, retention, and provision of access to information sources in support of the intellectual needs of a given library community”.
It clearly states the background work that goes into any and all decisions made within the library setting and reinforces that these decisions should be made with the end user in mind.
Gregory, V. (2019). Development and Management for 21st Century Library Collections: An Introduction. 2nd Ed. American Library Association.