Last Updated S012019


Unit Code MSR604


Unit Duration 1 Term (online) or 1 Semester (on-campus)



Master of Engineering (Safety, Risk and Reliability)

Duration 2 years



Year Level Two
Unit Creator / Reviewer Raj Sreenevasan
Core/Elective: Elective (Special Topic)


Pre/Co-requisites None
Credit Points


Masters total course credit points = 48

(12 credits (Thesis) + 3 credits x 12 (units))

Mode of Delivery

Online or on-campus.

Combination of modes: Online synchronous lectures; asynchronous discussion groups, videos, remote and cloud-based labs (simulations); web and video conferencing tutorials. High emphasis on personal and group self-study.  

Unit Workload

Total student workload including “contact hours” = 10 hours per week:

Lecture – 1 hour

Tutorial Lecture - 1 hour

Practical / Lab - 1 hour (if applicable)

Personal Study recommended - 7 hours

Unit Description and General Aims

(The special topics provide the opportunity to select a unit that is relevant to the industry. The special topics are carefully selected by the unit coordinator to enable the student to apply current technologies and the knowledge acquired from the entire course.)

The unit introduces engineers to Inherently Safer Design of plants and systems, green chemistry and green engineering principles.

An accident precursor is generally regarded as a warning of the potential for a more serious accident and hence the people responsible for the design and operation of the system must respond by identifying a ‘way of escape’. An inherently safer design is a design that eliminates or minimizes them significantly to reduce the potential consequences to people, environment, property and business. The concept of inherently safer design was first articulated by Trevor Kletz in 1978 and has been greatly elaborated since then (CCPS 1996, Kletz 1998 & 2014).

Although inherently safer design is the most robust way of addressing risk, for most existing facilities a complete risk management program also includes passive, active and procedural protections. A number of companies have developed systems that capture the essence of inherently safer design concepts advocated by Kletz and CCPS.

Learning Outcomes

On successful completion of this Unit, students are expected to be able to:

1. Apply various principles of inherently safer design to process plants

2. Reducing dust explosion risks by adopting inherently safer approaches

3. Prevent and mitigate process incidents by timely incorporation of inherently safer design

4. Incorporate the role of inherently safer design in process safety management systems

5. Ensure that an appropriate process safety culture is developed within the organization

Student assessment

Assessment Type

(e.g. Assignment - 2000 word essay (specify topic) Examination (specify length and format))

When assessed

(eg Week 5)

Weighting (% of total unit marks) Learning Outcomes Assessed

Assessment 1

Type: Quiz

Word length: n/a

Topic: Fundamental concepts of Inherently Safe Design.   

Week 5 20% 1, 2, 3

Assessment 2

Type: Report (Midterm Project)

[This will include a progress report; literature review, hypothesis, and methodology / conclusions]

Word length: 1000

Topic: Report on Simplification.   

Week 7 25% 1, 2, 3, 4

Assessment 3

Type: Report (Final Project)

[If a continuation of the midterm, this should complete the report by adding sections on: methodology, implementation / evaluation, verification / validation, conclusion / challenges and recommendations / future work. If this is a new report, all headings from the midterm and the final reports must be included.]

Word length: 2000

Topic example: Constraints on the development of friendlier plants.   

Week 12 35% 1, 2, 3, 4, 5

Practical Participation

Embedded in report on Simplification      

Continuous 15% 5

Class Participation


Continuous 5% 1-5


Prescribed and Recommended readings

Required Textbook

 T. Kletz, Process Plants – A handbook for Inherently Safer Design, 2nd Edition, CRC Press, 2010

Reference Materials

Number of peer-reviewed journals and websites (advised during lectures). Some examples are listed below.

  • Inherently Safer Chemical Processes: A Life Cycle Approach, 2 nd Edition, CCPS, 2008
  • D. Hendershot, Introduction to Inherently Safer Design, CCPS, 2010
  • N. G. Leveson, System Safety Engineering: Back to the Future, MIT, 1999
  • Guidance on Applying Inherent Safety in Design, 2nd Edition, Energy Institute, 2014
  • IDC /EIT notes and Reference texts as advised.
  • Other material advised during the lectures

Unit Content

One topic is delivered per contact week, with the exception of part-time 24-week units, where one topic is delivered every two weeks.


Topic 1 and 2

Inherently Safer Design – Concept and its Benefits

1. History of Inherent Safety

2. What are inherently safer and user-friendly plants?

3. Inherently Safer Design as an overall approach

4. Hierarchy of controls

5. Inherently Safer Design – The concept

6. Defence in Depth / Layers of Protection

7. Inherent Safety defined

8. Levels of Inherent Safety

9. Process risk management and Inherent Safety

10. Inherent safety in the resource industries


Topic 3

The role of Inherently Safer Concepts in Process Risk Management

1. Integrating Inherent Safety in process risk management systems

2. Timing for consideration of Inherently Safer options

3. Inherent Safety constraints

4. Resolving Inherent Safety issues

5. Inherently Safer strategies

6. Process safety management system elements

7. Safety culture

Topic 4

Inherently Safer Strategies

1. Definition of Inherently Safer strategies

2. Intensification or minimisation

3. Substitution

4. Moderation or attenuation

5. Limitation of effects

6. Simplification

7. Other strategies / ways of making plants friendlier

8. Integration v simplification – managing competing strategies


Topic 5

Intensification and Substitution

1. Process intensification

2. Reaction

3. Distillation

4. Heat Transfer

5. Other unit operations

6. Storage

7. Intensification by detailed design

8. Many small plants or a really big one?

9. The use of safer non-reactive agents

10. Choosing less hazardous processes

Topic 6

Moderation and Limitation of Effects

1. Attenuated reactions

2. Attenuated storage and transport

3. Limitation of effects by equipment design

4. Limitation of effects by changing reaction conditions

5. Elimination of hazards


Topic 7


1. The reasons for complexity

2. Stronger equipment can reduce relief systems

3. Resistant materials of construction can replaces protective instruments

4. Designs free from opportunities for human error

5. Design changes can avoid the need for better instrumentation

6. Relocation can avoid the need for complication

7. Simple technology can replace high or complex technology

8. Leave things out

9. Avoid moving parts

10. Following rules to the tee

11. Asking for too much flexibility

12. The importance of timing of the analyses


Topic 8

Ways of Making Plants Friendlier

1. Avoiding knock-on effects

2. Making incorrect assembly impossible

3. Making status clear

4. Tolerance of misuse

5. Ease of control / computer control

6. Instructions and other procedures

7. Passive safety

8. Safety culture


Topic 9

Inherently Safer Design in Preventing Dust Explosions

1. Dust explosion overview

2. Using hierarchy of controls

3. Intensification / substitution

4. Attenuation / simplification

5. Mitigation measures


Topic 10

Implementing Inherently Safer Design

1. Management Systems approach for Inherent Safety (IS)

2. Educational awareness

3. Organizational culture

4. Inherent safety reviews

5. Human factors and inherent safety reviews

6. Reactive chemicals screening

7. Inherent safety review training

8. Documenting the inherently safer design features of a process


Topic 11

Inherently Safer Design Regulatory Initiatives

1. Inherent Safety regulatory developments and issues

2. Experience with inherent safety regulations

3. Issues in regulating inherent safety

4. What prevents implementations of Inherent Safety (IS)

5. How to achieve maximum IS in a given situation

6. Constraints (cost, time, stage of project, management, etc.) on the development of friendlier plants (including topics discussed throughout this 12 unit course, such as availability)

7. The Influence of the Law

8. The measurement of friendliness

9. Responsible care – Is it better than regulation?

10. Demonstration of ALARP / cost-benefit analysis


Topic 12

Project and Unit Review

In the final week students will have an opportunity to review the contents covered so far. Opportunity will be provided for a review of student work and to clarify any outstanding issues. Instructors/facilitators may choose to cover a specialized topic if applicable to that cohort.

Project – due at end of term

Software/Hardware Used


  • Software: N/A

  • Version: N/A

  • Instructions:  N/A

  • Additional resources or files: N/A


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