What is deaccessioning and what guidelines should govern its use?

Deaccessioning is the process of removing an artwork from a collection.  This is a major decision for any public art program, and should only be completed after a detailed review process.  Public art is particularly susceptible to changes in public opinion and so it is important to insulate artworks from sharp fluctuations in taste or popularity.  The best way to do so is to establish a deaccessioning policy well ahead of any need to employ it.  For a sample deaccessioning policy, see:
Depending on the laws governing your program, deaccessioned artworks may be sold, traded, transferred, or destroyed.  If an artwork is sold, then the proceeds should always be directed to the collection (or creation of new work) and never to administrative, overhead, or other funding needs—selling an artwork to keep the lights on undercuts the core operating principles for most public art programs.  You can learn more about deaccessioning by accessing the Demystifing the Deaccession Process Webinar and curated resources.