The word safety is used in the following ways:

  1. Safety - preventing bad things happening.
  2. A safety critical system (SCS) or life critical system is a system whose failure or malfunction may result in one (or more) of the following outcomes: death or serious injury to people. loss or severe damage to equipment/property or environmental harm.
  3. Safety is also used in specifications: "Informally, a safety property stipulates that "bad things" do not happen during execution of a program and a liveness property stipulates that "good things" do happen (eventually) (Lamport 1977). ... Thus, knowing whether a property is safety or liveness helps when deciding how to prove that the property holds."