Page 346 - Intro Predictive Maintenance

Establishing a Predictive Maintenance Program 337

Accuracy

Decisions on machine-train or plant system condition will be made based on the data
acquired and reported by the predictive maintenance system. It must be accurate and
repeatable. Errors can be input by the microprocessor and software as well as by the
operators. The accuracy of commercially available predictive maintenance systems
varies. Although most will provide at least minimum acceptable accuracy, some are
well below the acceptable level.

It is extremely difficult for the typical plant user to determine the level of accuracy of
the various instruments that are available for predictive maintenance. Vendor litera-
ture and salespeople will attempt to assure the potential user that their system is the
best, most accurate, and so on. The best way to separate fact from fiction is to compare
the various systems in your plant. Most vendors will provide a system on consign-
ment for up to 30 days. This will provide sufficient time for your staff to evaluate each
of the potential systems before purchase.

Training and Technical Support

Training and technical support are critical to the success of your predictive
maintenance program. Regardless of the techniques or systems selected, your staff
will have to be trained. This training will take two forms: system users’ training and
application knowledge for the specific techniques included in your program. Few, if
any, of the existing staff will have the knowledge base required to implement the
various predictive maintenance techniques discussed in the preceding chapters. None
will understand the operation of the systems that are purchased to support your
program.

Many of the predictive systems’ manufacturers are strictly hardware and software ori-
ented. Therefore, they offer minimal training and no application training or technical
support. Few plants can achieve minimum benefits from predictive maintenance
without training and some degree of technical support. It is therefore imperative that
the selected system or system vendors provide a comprehensive support package that
includes both training and technical support.

System Cost
Cost should not be the primary deciding factor in system selection. The capabilities
of the various systems vary greatly, and so does the cost. Care should be taken to
ensure a fair comparison of the total system capability and price before selecting your
system. For example, vibration-based systems are relatively competitive in price. The
general spread is less than $1,000 for a complete system; however, the capabilities
of these systems are not comparable. A system that provides minimum capability for
vibration monitoring will be about the same price as one that provides full vibration-
monitoring capability and provides process parameter, visual inspection, and point-
of-use thermography.