Page 351 - Intro Predictive Maintenance

342 An Introduction to Predictive Maintenance

User-Friendly Operation. The software program should be menu-driven with
clear online user instructions. The program should protect the user from distorting
or deleting stored data. Some of the predictive maintenance systems are written in
DBASE software shells. Even though these programs provide a knowledgeable user
with the ability to modify or customize the structure of the program (e.g., report
formats), they also provide the means to distort or destroy stored data. A single key
entry can destroy years of stored data. Protection should be built into the program to
limit the user’s ability to modify or delete data and to prevent accidental database
damage.

The program should have a clear, plain language user’s manual that provides the logic
and specific instructions required to set up and use the program.

Automatic Trending. The software program should be capable of automatically
storing all acquired data and updating the trends of all variables. This capability should
include multiple parameters, not just a broadband or single variable. This will enable
the user to display trends of all variables that affect plant operations.

Automatic Report Generation. Report generation will be an important part of the
predictive maintenance program. Maximum flexibility in format and detail is
important to program success. The system should be able to automatically generate
reports at multiple levels of detail. At a minimum, the system should be able to
report:

• A listing of machine-trains or other plant equipment that has exceeded or
is projected to exceed one or more alarm limits—The report should also
provide a projection to probable failure based on the historical data and last
measurement.
• A listing of missed measurement points, machines overdue for monitoring,
and other program management information—These reports act as
reminders to ensure that the program is maintained properly.
• A listing of visual observations—Most of the microprocessor-based
systems support visual observations as part of their approach to pre-
dictive maintenance. This report provides hard copies of the visual
observations as well as maintaining the information in the computer’s
database.
• Equipment history reports—These reports provide long-term data on the
condition of plant equipment and are valuable for analysis.

Simplified Diagnostics. Identification of specific failure modes of plant equipment
requires manual analysis of data stored in the computer’s memory. The software
program should be able to display, modify, and compare stored data in a manner that
simplifies the analysis of the actual operating condition of the equipment. At a
minimum, the program should be able to directly compare data from similar machines,
normalize data into compatible units, and display changes in machine parameters (e.g.,
vibration, process).