Lecture 2 - Risk Assessment

Question 1

What is the purpose of risk identification?

Answer 1

The purpose of risk identification is to FIND, RECOGNISE and DESCRIBE risks that might help or prevent an organization achieving its objectives.

Question 2

How do you determine what risks to assess?

Answer 2

– Specific hazards
– Specific hazardous sequences
– Specific events
– Scenarios (also known as chains of events)

• In addition, organisations need to consider related to achieving their objectives such as:
  – Changes in external and internal contexts
  – Emerging risks,
  – Threats and opportunities.

Question 3

How can risks be analysed?

Answer 3

• Risk analysis provides an input to decisions on whether risks need to be treated and the most appropriate and cost-effective risk treatment strategies.
• Risk analysis involves consideration of the sources of risk, their positive and negative consequences and estimation of likelihood.
• In most circumstances existing controls are taken into consideration.

Question 4

What is Estimation of likelihood for risk assessment

Answer 4

• Component reliability analysis (Chapter 3*)
  – Based on estimation of parameters for distributions of life/ failure or other features of interest
• System reliability analysis
  – Reliability block diagrams (Ch. 4.1)
  – Fault Tree Analysis (Ch 4.2)
  – Event Tree Method (Ch 4.3*)
• Failure Mode and Effects Analysis FMEA/FMECA (Ch 4.5*)
• Specialist methods
  – Probability of failure of a Safety Instrumented System (SIS) using LOPA (Layer of Protection analysis)
  – Probability of Failure on Demand (PFD)