Over
the past twenty years, maintenance has changed, perhaps more so than any
other management discipline. The changes are due to a huge increase in the
number and variety of physical assets (plant, equipment and buildings) which
must be maintained throughout the world, much more complex designs, new
maintenance techniques and changing views on maintenance organization and
responsibilities.
Maintenance is also responding to changing expectations. These include a
rapidly growing awareness of the extent to which equipment failure affects
safety and the environment, a growing awareness of the connection between
maintenance and product quality, and increasing pressure to achieve high
plant availability and to contain costs.
The
changes are testing attitudes and skills in all branches of industry to the
limit. Maintenance people are having to adopt completely new ways of
thinking and acting, as engineers and as managers. At the same time the
limitations of maintenance systems are becoming increasingly apparent, no
matter how much they are computerized.
In the
face of this avalanche of change, managers everywhere are looking for a new
approach to maintenance. They want to avoid the false starts and dead ends
which always accompany major upheavals. Instead they seek a strategic
framework which synthesizes the new developments into a coherent pattern, so
that they can evaluate them sensibly and apply those likely to be of most
value to them and their companies.
This
book describes a philosophy which provides just such a frame-work. It is
called
Reliability-centered Maintenance,
or RCM.
If it
is applied correctly, RCM transforms the relationships between the
undertakings which use it, their existing physical assets and the people who
operate and maintain those assets. It also enables new assets to be put into
effective service with great speed, confidence and precision.
This
chapter provides a brief introduction to RCM, starting with a look at how
maintenance has evolved over the past fifty years.
1.2
Reliability-Centered Maintenance
Since the
1930's, the evolution of maintenance can be traced through three
generations. RCM is rapidly becoming a cornerstone of the Third Generation,
but this generation can only be viewed in perspective in the light of the
First and Second Generations.
The
First Generation
The
First Generation covers the period up to World War II. In those days
industry was not very highly mechanized, so downtime did not matter much.
This meant that the prevention of equipment failure was not a very high
priority in the minds of most managers. At the same time, most equipment was
simple and much of it was over-designed. This made it reliable and easy to
repair. As a result, there was no need for systematic maintenance of any
sort beyond simple cleaning, servicing and lubrication routines. The need
for skills was also lower than it is today.
The
Second Generation
Things
changed dramatically during World War II. Wartime pressures increased the
demand for goods of all kinds while the supply of industrial manpower
dropped sharply. This led to increased mechanization. By the 1950's machines
of all types were more numerous and more complex. Industry was beginning to
depend on them.
As this
dependence grew, downtime came into sharper focus. This led to the idea that
equipment failures could and should be prevented, which led in turn to the
concept of preventive maintenance. In the 1960's, this consisted mainly of
equipment overhauls done at fixed intervals.
The
cost of maintenance also started to rise sharply relative to other operating
costs. This led to the growth of maintenance planning and control systems.
These have helped greatly to bring maintenance under control, and are now an
established part of the practice of maintenance.
Finally, the amount of capital tied up in fixed assets together with a sharp
increase in the cost of that capital led people to start seeking ways in
which they could maximize the life of the assets.
The
Third Generation
Since
the mid-seventies, the process of change in industry has gathered even
greater momentum. The changes can be classified under the headings of new
expectations, new research and new techniques.
|