Definitions
Safety -- "...freedom from unacceptable risk of physical injury or of damage to the health of people, either directly, or indirectly as a result of damage to property or to the environment..."
Functional Product Safety -- the product's ability to operate correctly guaranteeing correct mission critical operation in response to its inputs. Functional safety can be affected by a wide variety of factors including: random hardware failures, systematic hardware failures, software errors, common cause failures, human error, environmental influences (e.g. electromagnetic, temperature, mechanical phenomena), supply system voltage disturbances (e.g. loss of supply, reduced voltages, re-connection of supply).
