1. Introduction to
Maintenance Engineering

2. Introduction
The Oxford dictionary meaning of “to maintain” is to
“cause something to continue” or “to keep
something in existence at the same level”.
“Maintenance is the process of maintaining an item
in an operational state by either preventing a
transition to a failed state or by restoring it to an
operational state following failure”

3. Introduction
Maintenance engineering is typically
defined as a staff function whose prime
responsibility is to ensure that
maintenance techniques are effective,
equipment is designed and modified to
improve maintainability, ongoing
maintenance technical problems are
investigated, and appropriate corrective
and improvement actions are taken.

4. Purpose of Maintenance
The purpose of maintenance is to produce
reliable plant capacity. The company vision
for producing a profitable product should
understand that effective maintenance
provides reliable plant capacity. Some of
the most important maintenance decisions
are made before a company even builds a
plant.

5. Purpose of Maintenance
Gifford Brown (1993) of Ford Motor
Company explains the 1-10-100 Rule. This
rule means that every $1 spent up front
during engineering to reduce maintenance
eliminates a later $10 cost to maintain
equipment properly or $100 in breakdown
maintenance.

6. Purpose of Maintenance
It means that every company has to maintain
operable with due efficiency and effectiveness of its
fixed assets. Encompasses all activities necessary
for:
- Maintain a facility or equipment in operation
-Reset the operation of equipment to original
condition.
The maintenance impact, therefore, the quantity and
quality of production.

7. Responsibility of the
Maintenance
 The principal responsibility of maintenance is to provide a service to
enable an organization to achieve its objectives. The specific
responsibilities vary from one organization to another; however they
generally include the following according to Duffuaa et al. (1998):
 1. Keeping assets and equipment in good condition, well
configured and safe to perform their intended functions;
 2. Perform all maintenance activities including preventive,
predictive; corrective, overhauls, design modification and
emergency maintenance in an efficient and effective manner;
 3. Conserve and control the use of spare parts and material;
 4. Commission new plants and plant expansions; and

8. “Maintenance Philosophy”
Based on the timing and the work
contents involved in the maintenance
task, different maintenance
philosophies can be put in the
following categories, viz.:

9. “Maintenance Philosophy”
1. Timing known, content known:
preplanned maintenance (PPM),
planned shutdowns, routine
inspections, and scheduled change-
outs fall in this category;

10. “Maintenance Philosophy”
2. Timing known, content unknown:
statutory surveys, third party
inspections, and condition-based
maintenance;

11. “Maintenance Philosophy”
3. Timing unknown, content known:
anticipated maintenance work,
contingency work awaiting shutdown,
and run to destruction; and

12. “Maintenance Philosophy”
4. Timing unknown, content
unknown: break-down maintenance,
immediate repairs arising from
inspection, and run to failure.

13. Maintenance Scope Changed with
Time
In recent times, there has been tremendous
growth in maintenance concepts and
techniques. The change in emphasis includes:
Decision support tools, such as hazard studies,
failure modes and effects analyses, and expert
systems.
New maintenance techniques such as condition
monitoring or CMMS.
Designing equipment with emphasis on
reliability and maintainability.
A major shift in organizational thinking towards

14. Approaches to Maintenance
There are several approaches to maintenance,
and different approaches are applicable based
on the expected use and maintenance schedule
of an item.
Economic considerations are tightly related to
maintenance and the system lifecycle; it is clear
that failure to consider a design’s effects on
maintenance, and vice versa, can have adverse
effects on profit.

15. Approaches to Maintenance
Maintenance has been categorized based on the
nature and purpose of the maintenance work and
on its frequency. Generally, there are four (basic)
types of maintenances in use, viz., preventive,
corrective, predictive, and fault-finding.

16. Approaches to Maintenance
Maintenance can also be classified according to
the degree to which the maintenance work is
carried out to restore the equipment relative to its
original state. This leads to the following
categorization:
Perfect maintenance is maintenance which restores
the equipment to as good as new condition.

17. Approaches to Maintenance
Minimal maintenance results in equipment having the
same failure rate as it had before the maintenance
action was initiated. This is also called the as bad as
old state.
Imperfect maintenance is maintenance in which the
equipment is not restored to as good as new, but to a
relatively younger state (a state in between as good as
new and as bad as old).

18. Approaches to Maintenance
Worse maintenance: This type of maintenance results
(unintentionally) in an increase of the equipment’s
failure rate or actual age but does not result in
breakdown.
Worst maintenance: This type of maintenance results
(unintentionally) in the equipment’s breakdown.