Page 74 - Electric Drives and Electromechanical Systems

Chapter 2 Analysing a drive system 67

FIG. 2.16 Risk management model showing the path from the triggering event to the undesired event and the
subsequent risk.

Enabling estimates to be made of the likelihood of each type of physical failure
and other undesired events.
Assessing the resulting risks.
Determining the control measures that could reduce the likelihood of undesired
events and mitigate their consequences.
The following five step methodology for dealing effectively with hazards has been
found to be effective:
1. Review existing standards. These will include those provided by the British
Standards Institute (BSI), Institution of Engineering and Technology, American
National Standards Institute, Underwriters Laboratory, and Institution of Electronic
and Electrical Engineers. This review will determine if standards and requirements
exist for the product or system being considered.
2. Identify known hazards. Studying recognised standards should make it possible to
identify the hazards usually associated with a system. This activity will also involve
a detailed audit of the software and any network interconnections.
3. Identify unknown hazards. These hazards include those identified in standards that
must be eliminated. The design team must follow a systematic approach to identify
these undiscovered hazards lurking within the design and in its use or misuse by