Be able to give the definitions of the following terms:

Safety:

  [Absolute definition]
  Freedom from accidents or loss.

  [Relative definition]
  Freedom from unacceptable risk

Accident: 

  An undesired and unplanned event that results in a loss (including loss of human life, injury, property damage, etc.)
  that is important to a stakeholder.

Incident:

  Incident (aka near miss) -- an event that involves no loss (or only minor loss) but with the potential for loss 
  under different environmental circumstances. 

Hazard:

  [Leveson -- safer world definition]
  “state or set of conditions of a system (or an object) that, together
  with a particular set of worst-case environment conditions, will lead
  to an accident (loss event)” [Leveson, Safer World, p. 467]

  [Three components of a hazard -- Ericson]
  A hazard is compromised of the following three components, each of
  which must be present in order for the hazard to exist
   * Hazardous Element (HE) – The basic hazardous resource creating the
    impetus for the hazard, e.g., electric shock, explosives being used in
    the system, a harmful chemical, kinetic energy, etc.
   * Initiating Mechanism (IM) – The trigger or initiating event(s)
    (or states) causing the hazard to occur.  This is the mechanism
    that causes actualization of the hazard from a dormant state to an actual mishap.
   * Target and Threat (T/T) – Person or thing that is vulnerable to
    injury or damage, along with the specific threat (harm) to the person/thing.

  [characteristics of a hazard that form the basis of risk]
  * Severity -- the worst possible accident (harm) that could result
  from the hazard given the environment in its most unfavorable state
  * Likelihood of occurrence of the accident (harm)

Risk: 
  combination of the likelihood of occurrence of harm and the
  severity of that harm 

State:

  A particular configuration of a system including the current values of system’s computer memory and resources,
  conditions and positions of mechanical components, etc.

Event:

  A transition from one state to another, or something of particular interest that causes a transition 
  from one state to another

Reliability:

  the probability that a piece of equipment or component will perform
  its intended function satisfactorily for a prescribed time and under
  stipulated environment conditions. [Leveson, Safeware, p. 172]

 * explain the different between safety and reliability (give examples)