Reliability Engineering

Following the principle of Docendo discimus, (Latin "by teaching, we learn"), I decided to speak on Process Plant Maintenance, at an upcoming symposium, leaving 9 other plum topics to my good friends. It is a subject that evokes the depressing picture of a greasy-faced worker in blue overalls with spanner and wrench in hand. Being the prime mover of the symposium, I can take liberties with titles and so I decided to sex it up by renaming it “Reliability Engineering”. My mandate to each speaker is to fire 10 takeaway bullets in 20 minutes. So here are my 10 bullets on “Reliability Engineering” as applied to Chemical Industry. 

1)   The Bathtub Curve
 
The diagram is self-explanatory. The trick is to be able to tell the transition times and prepare accordingly.

2)   Four Kinds of Maintenance

a)   Breakdown maintenance

b)   Preventive maintenance

c)   Predictive maintenance

d)   Reliability centered maintenance

3)   Maintenance Cost

a)   Downtime cost : Loss of production

b)   Spare part cost (including the cost of carrying it)

c)   Special tools, tackles and rigs

d)   Specialist engineers/technicians

e)   Stress of shutdown and restart

f)    Risk of collateral damage

4)   Design to Minimize Maintenance

Examples : a) Oil mist lubrication. b) Low speed machinery which will improve bearing life.

5)   Validation of Design Assumptions

Periodic maintenance should revalidate design assumptions like fouling factor (heat exchangers) and air ingress (vacuum system)

6)   Access for Maintenance

Poor access will increase time and cost and can compromise safety. To be addressed in design phase by maintainability study.

7)   Safety During Maintenance

~30% of fatalities in manufacturing industry are associated with maintenance activity.

8)   Emergency Equipment

Periodic health check for safety valves, shut-off valves, firefighting equipment etc

9)   Spares Management

To stock or not to stock?

10)  Internet of Things (IoT)

Sensors embedded in equipment check for abnormal conditions and trigger work orders when safe operating limits are breeched. IoT is expected to move Reliability Engineering into a whole new orbit.

Knowledge – Skill Dichotomy in Engineering

Yesterday I spoke at an engineering college festival. The creativity and enthusiasm of students was heartening. In the afternoon they had planned a workshop on use of a popular software tool for heat exchanger design. My task was to prime them for this workshop. During the Q&A session at the end of my talk, I sensed a significant lack of grasp of fundamentals among students. Later while having lunch with some of the faculty, I learned that the popular software tool has now been appropriated into the syllabus; the intention being to enhance the employability of students. This revelation was quite disconcerting. 

Universities are where students seek knowledge. They gather knowledge and hone it by interaction with teachers and other students. Universities also build character, but that is not the subject of this blogpost. When teachers and students are already struggling to complete the traditional chemical engineering curriculum, any new initiative to impart skills on software application has to be at the expense of time allotted for fundamental studies. 

In engineering, unlike trades, skill cannot be a substitute for knowledge. Teachers also probably find it easier to impart skills rather than knowledge. This is an adverse fall-out of the burgeoning coaching class industry. It is also a collateral damage of the IT explosion, which is more skill than knowledge based. An obsession with tool numbs the mind and makes it less open to new ideas. Chemical engineering, which is more science based than other engineering disciplines, can ill afford such a mindset in its practitioners. 

Do skills, like mastery of a specific software tool, increase the employability of engineers? The answer is an unequivocal no. Skills are best learned on the job and industry is more than willing to invest time and effort towards this. Skills are also job specific and there is no one shoe that fits all. Once engineers enter industry, they will have very little time and inclination to revisit the underlying principles of their practice. Universities are the best place for engineers to acquire knowledge and this is a tradition worth preserving.