The document discusses key concepts and terminology related to hazard evaluation (HE) and risk assessment. It describes hazards as conditions that could lead to future mishaps or accidents, and explains that hazards have an inherent probability and severity of risk. Hazards are composed of three components: hazardous events (HE), initiating mechanisms (IM), and time/targets (T/T). The HE and IM establish the probability of a mishap, while T/T and some aspects of HE and IM determine mishap severity. Hazard causal factors can be characterized on three levels. While a hazard's existence is binary, the probability of a mishap depends on specific causal factors. The document lists topics to be elaborated in an

1. Unit: 1 Lecture: 3 & 4
Dr. Jayanta Kr. Mahato
Associate Professor
Mechanical Engineering Dept.
Shobhit University, Meerut
Key Concept & Terminology:
HE and Risk Assessment

2. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut

3. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut

4. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut

5. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut
Entropy Risk Model

6. Hazard causal factor model
Level 1: Top Layer The three
hazard components (HE, IM, T/T)
Level 2: Midlevel The HCF
categories [hardware, software,
human system integration (HSI),
environment, functions,
interfaces]
Level 3: Bottom Level The
detailed specific causes (failure
modes, errors, etc.

7. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut

8. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut

9. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut
 Hazards cause mishaps; a hazard is a condition that defines a possible future event
(i.e., mishap).
 A hazard and a mishap are two different states of the same phenomenon (before
and after).
 Each hazard/mishap has its own inherent and unique risk (probability and severity).
 A hazard is an entity comprised of three components (HE, IM, T/T).
 The HE and IM are the HCFs and they establish the mishap probability risk factor.
 The T/T along with parts of the HE and IM establish the mishap severity risk factor.
 HCFs can be characterized on three different levels.
 The probability of a hazard existing is either 1 or 0; however, the probability of a
mishap is a function of the specific HCFs.
Summery

10. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut

11. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut

12. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut

13. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut

14. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut

15. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut

16. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut
As Low As Reasonably Practicable

17. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut
System Life Cycle (SLC)
You Know Till Now
 Hazard
 Hazard Triangle
 HE
 IM
 T/T
 Hazard Actuation
 Hazard Causal
Factors (HCFs)
 Safety Domain
Ontology
(Transition Path)
 Risk Assessment
 Risk Perception

18. Dr. Jayanta Kr. Mahato,
Assoc. Prof., Mechanical Engg. Dept.
Shobhit Institute of Engg. and Tech.
(Deemed to be University), Meerut
Assignment
 Elaborately Discussed the followings
 Basic Terminologies (Safety, Accident, Hazard, Mishap, Risk, Risk Assessment etc..)
 Hazard Triangle
 HE
 IM
 T/T
 Hazard Actuation
 Hazard Causal Factors (HCFs)
 Safety Domain Ontology (Transition Path)
 Risk Assessment
 Risk Perception
 Prevention through Design (PtD)