Page 396 - Intro Predictive Maintenance

A Total-Plant Predictive Maintenance Program 387

Table 16–3 Criteria for Preventive Maintenance Repair Method

Repair Separate from PM Repair with PM
Enables more accurate scheduling of Best if:
PM, at consistent times. Equipment is difficult to get from production.
Allows use of inspection specialists with Extensive tear down is involved that would
separate repair experts. have to be repeated for separate repairs.
Allows parts, tools and documents to Extensive travel time is required to return to
be obtained as required, instead of the location.
carrying extensive inventory. It is difficult for the person discovering the
problem to describe it to another repair person.

extensive preparation and access time should make repairs at the same time as
preventive tasks. If, however, the workforce is large enough to be specialized and
supports large numbers of similar equipment that are located close together, then
the inspection/preventive maintenance function should be separated from repairs. In
general, most manufacturing plants should do repairs separately from preventive tasks.
Most field service personnel will do both at the same time.

Data Gathering

Maintenance management needs data, but maintenance personnel do not like to report
data. Given this disparity between supply and demand, everything possible should be
done to minimize data requirements, make data easy to obtain, and enforce accurate
reporting. The main information needed from inspection and preventive activity is as
follows:

• That the job was done
• Equipment used in meter reading
• Part numbers of any parts replaced
• Repair work requests to fix discovered problems
• Time involved

As preventive maintenance sophistication increases toward predictive maintenance,
the test measurements should be recorded so that signature and trend analysis with
control limits can be used to guide future maintenance actions.

16.3 CONCLUSION
The following points summarize some of the main concepts in the preceding
discussions:

• Preventive maintenance is necessary for most durable hardware.
• Preventive maintenance enables preaction, which is better than reaction.
• It is necessary to plan.