Basic Principles of Machinery Health Monitoring

Hi,

As promised, this second entry will discuss Machinery Health, or Condition Monitoring, describing a few basic principles.

First Machinery Health Monitoring is a subset of 'maintenance', where maintenance is defined as:

"Activities to preserve the functions of machinery, required by the machinery stakeholders, in a defined operating context".

Many people think that maintenance is about preserving machinery, this is unsatisfactory as the focus is too narrow.  Modern expectations in society for machinery to be safe, non polluting to the environment and deliver a superior user experience means maintenance has to go beyond 'machinery preservation'.  A machine does not necessarily have to be physically broken to be functionally failed.

Consider the maintenance requirements of a racing car, whilst it is being actively raced, compared with exactly the same car used in a museum (because its racing career was so successful).  Would you think the functional requirements for the same car in completely different operating environments are going to be the same?  If not, neither will the maintenance required, be the same.  This point also illustrates that machinery operating contexts are vital in determining an optimal maintenance regime.

Who are the stakeholders?  obsolete maintenance thinking would only include the user of the machinery (as in operator and maintainer) and perhaps the owner.  This leaves out many other groups who may have a completely legitimate interest (because there is an impact on them) in the machinery.  A prime example may be a members of the general public who until recently lived in close proximity to the Fukushima Nuclear plant?  Stakeholders include The Government and regulators, as there is more and more legislation that applies to running and maintaining machinery.  Financiers and insurers also have direct interests as do the customers who use the machinery (e.g. transport) or use the products from machinery (e.g. electricity).

One thing which may not be obvious, is what constitutes failure?  failure to deliver comprehensive stakeholder functional requirements is functional failure, but at what level?  stakeholders may differ (in terms of impact on them or their perception of risk of impact) in what functional failure actually is.  When defining a maintenance regime, this must not be underestimated.

This will do for this entry.  I will try and keep these short and sharp as I can.  I am always interested in comments or feedback.

Regards - Charlie

Introduction

Hello,

I am not sure if I will have time to sustain this, but I would like to use this to reflect on some aspects of my work and life, to share some things and see if anyone responds.

I am an Engineer (not software) who specialises in machinery condition and health.  This is an emerging discipline and as yet has further development to reach maturity.  It is this that makes it interesting and exciting, nobody knows what it will look like when it reaches maturity.

My background is in the Royal Navy Submarine Service, where I had the distinct advantage of an Apprenticeship and over twenty year full service career.  The depth of my training and breadth of experience both operating and maintaining Nuclear propulsion plants, and submarine systems has stood me in excellent stead in my further career in industry.  I find I can easily empathise with engineering colleagues working in completely different industries.

I am married to Diana, we both have our daughters Natalie and Nuala, who have both flown the nest.  I cannot believe we are grandparents Ellen 10 and Oliver just under 1 (but its great).  When did that all happen?

My university education was with the UK Open University, to whom I will be eternally grateful because of the easy and universal access to education it provided.  It was one of two things Harold Wilson (an ex prime minister) ever did for the UK, the first was keeping the UK out of the Vietnam War and the second establishing the OU.  I now have a Bachelors in Computer Science and a Masters degree in Information Systems.  My education and experience blend perfectly for my work in machinery health and condition.

So to finish this entry a small introduction is probably appropriate, what is Machinery Health or condition?  Many machines have sensors which measure things like temperatures and pressures, which over the last 20 years have been connected to digital electronics and control systems (think about modern cars - car engine control is digital).  You can analyse trends of the sensor's data and look for problems in the running of machines.  Machinery health monitoring is just like a doctor who diagnoses illness in people.  We both look for symptoms and then we recognise that a certain pattern of symptoms equates to a health problem.  The pattern recognition process is diagnosis.

In my next entry I will start expanding on how this is done, and what my personal take on all this is.  Hopefully a few of you out there will share my interests and interact.

Best regards,

Charlie