What is "parkinson's law"

1955 (in the "Economist" of Nov. 19), named for its deviser, British historian and journalist Cyril Northcote Parkinson (1909-1993): "work expands to fill the time available for its completion."

Originally, Parkinson's law is the adage that "work expands so as to fill the time available for its completion", and the title of a book which made it well-known. However, in current understanding, Parkinson's law is a reference to the self-satisfying uncontrolled growth of the bureaucratic apparatus in an organization.