Do you have a definition for
preventive maintenance?
Test: Ask people in maintenance and
operations to define what is included in preventive maintenance.
Having a definition of preventive
maintenance is important for good communication in meetings, improvement
efforts, and training. For example, are detailed cleaning, balancing, and
alignment part of preventive maintenance? Is operator inspection part of PM?
Are operating practices part of PM?
Do you know how satisfactory PM
is done today?
Test: Ask the plant manager, maintenance
manager, and operations manager for the PM improvement plan. If there is one,
is it specific with timelines?
For example:
“Lubrication storage improvement complete by September 2003.”
Do you have an alignment
standard, and is it followed?
Test: Ask for an alignment standard and
check quality of standard. Go look at equipment for signs of good or poor
alignment.
Do you have a lubrication
standard, and it is followed?
Test: The standard should include storage,
handling, filtering, and cleanliness of lubricants. Visually check cleanliness
of storage areas and handling.
Are inspections (condition
monitoring) done where it is cost effective to do so?
Test: Go through inspection lists, check
for level of detail, and make sure the route is actually completed
Comparison of Four Maintenance Programs (Piotrowski 2001)
1.
Reactive Maintenance (Breakdown or
Run-to-Failure Maintenance)
Basic philosophy:
• Allow machinery to run to failure.
• Repair or replace damaged equipment when obvious problems occur.
The advantages of this approach are that it works well if equipment
shutdowns do not affect production and if labor and material costs do not
matter.
2.
Preventive Maintenance (Time-Based
Maintenance)
Basic
philosophy:
• Schedule maintenance activities at predetermined time intervals.
• Repair or replace damaged equipment before obvious problems occur.
This
philosophy entails the scheduling of maintenance activities at predetermined
time intervals, where damaged equipment is repaired or replaced before obvious
problems occur. The advantages of this approach are that it works well for
equipment that does not run continuously, and with personnel who have enough
knowledge, skills, and time to perform the preventive maintenance work.
3.
Predictive Maintenance (Condition-Based
Maintenance)
Basic
philosophy:
• Schedule maintenance activities when mechanical or operational
conditions warrant.
• Repair or replace damaged equipment before obvious problems occur.
When the
condition gets to a predetermined unacceptable level, the equipment is shut
down to repair or replace damaged components so as to prevent a more costly
failure from occurring. In other words, “Don’t fix what is not broke.” Advantages
of this approach are that it works very well if personnel have adequate
knowledge, skills, and time to perform the predictive maintenance work, and
that it allows equipment repairs to be scheduled in an orderly fashion.
4.
Reliability Centered Maintenance
(Pro-Active or Prevention Maintenance)
Basic
philosophy:
·
Utilizes predictive/preventive maintenance
techniques with root cause failure analysis to detect and pinpoint the precise
problems, combined with advanced installation and repair techniques, including
potential equipment redesign or modification to avoid or eliminate problems
from occurring.
Since
maintenance work is performed only when it is needed, and extra efforts are put
forth to thoroughly investigate the cause of the failure and determine ways to
improve machinery reliability, there can be a substantial increase in
production capacity.
The road from a purely reactive program to
a RCM program is not an easy one. The following is a list of some basic steps
that will help to get moving down this path:
1. Develop a
Master equipment list identifying the equipment in your facility.
2.
Prioritize the listed components based on importance or criticality to
operation, process, or mission.
3. Assign
components into logical groupings.
4. Determine
the type and number of maintenance activities required and periodicity using:
a. Manufacturer technical manuals
b. Machinery history
c. Root cause analysis findings – Why did it fail?
d. Good engineering judgment
5. Assess the size of maintenance staff.
6. Identify tasks that may be performed by
operations maintenance personnel.
7. Analyze equipment failure modes and impacts
on components and systems.
8. Identify effective maintenance tasks or
mitigation strategies.
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