INTRODUCTION TO THE
THEORY AND PRACTICE
R. Keith Mobley
President, The Plant Performance Group,
As with any discipline built upon the foundations of science and technology, the study of maintenance
begins with a definition of maintenance. Because so many misconceptions about this definition
exist, a portion of it must be presented in negativeterms. So deeply, in fact, are many of
these misconceptions rooted in the minds of management and many maintenance practitioners that
perhaps the negatives should be given first attention.
Maintenance is not merely preventive maintenance, although this aspect is an important ingredient.
Maintenance is not lubrication, although lubrication is one of its primary functions. Nor is
maintenancesimply a frenetic rush to repair a broken machine part or building segment, although
this is more often than not the dominant maintenance activity.
In a more positive vein, maintenance is a science since its execution relies, sooner or later, on
most or all of the sciences. It is an art because seemingly identical problems regularly demand and
receive varying approaches and actions and becausesome managers, foremen, and mechanics display
greater aptitude for it than others show or even attain. It is above all a philosophy because it is
a discipline that can be applied intensively, modestly, or not at all, depending upon a wide range of
variables that frequently transcend more immediate and obvious solutions. Moreover, maintenance
is a philosophy because it must be as carefullyfitted to the operation or organization it serves as a
fine suit of clothes is fitted to its wearer and because the way it is viewed by its executors will shape
Admitting this to be true, why must this science-art-philosophy be assigned—in manufacturing,
power production, or service facilities—to one specific, all-encompassing maintenance department?
Why is it essential toorganize and administer the maintenance function in the same manner that
other areas are so handled? This chapter will endeavor to answer these questions. This handbook will
develop the general rules and basic philosophies required to establish a sound maintenance engineering
organization. And, it will also supply background on the key sciences and technologies that
underlie the practice ofmaintenance.
Let us, however, begin by looking at how the maintenance function is to be transformed into an
operation in terms of its scope and organization, bearing in mind its reason for being—solving the
day-to-day problems inherent in keeping the physical facility (plant, machinery, buildings, services)—
in good operating order. In effect, what must the maintenance function do?
Unique though actual maintenance practice may be to a specific facility, a specific industry, and a
specific set of problems and traditions, it is still possible to group activities and responsibilities into
two general classifications: primary functions that demand daily work by the department; secondary
ones assigned to the maintenance department for reasons of expediency,know-how, or precedent.
Maintenance of Existing Plant Equipment. This activity represents the physical reason for the
existence of the maintenance group. Responsibility here is simply to make necessary repairs to production
machinery quickly and economically and to anticipate these repairs and employ preventive
maintenance where possible to prevent them. For this, a staff of skilledcraftsmen capable of performing
the work must be trained, motivated, and constantly retained to assure that adequate maintenance
skills are available to perform effective maintenance. In addition, adequate records for
proper distribution of expense must be kept.
Maintenance of Existing Plant Buildings and Grounds. The repairs to buildings and to the external
property of any plant—roads,...