MRO (maintenance and repair)

In accordance with the definition, the data in GOST 18322—78 (valid in Ukraine on 01/01/22) the system of maintenance and repair of equipment is a set of interrelated means, documentation of maintenance and repair and the performers necessary to maintain and restore the quality of products included in this system.

The MRO system should provide:

• maintaining equipment in working condition and preventing unexpected failures
• optimal organization of equipment maintenance and repair
• increase in the coefficient of technical use of equipment by improving the quality of maintenance and repair and reducing equipment downtime
• the ability to perform repair work on schedule, consistent with the production plan
• timely preparation of necessary spare parts and materials

In general, the MRO system provides the following types of maintenance and repairs:

1) maintenance

2) current repair

3) average repair

4) overhaul

Since very diverse equipment is used in various industries, as well as in connection with the established practice, the types and methods of maintenance and repair may differ from those specified in GOST. For example, average repair may not be carried out. But still, without losing generality, you can disclose the contents of the above types of maintenance and repair as follows.

Maintenance:

• every shift (cnt O-2, TO-3)
• seasonal maintenance
• in special conditions
• other types of maintenance

The maintenance of TO-1 … Seasonal TO largely depends on the type of equipment; For some types, these services may not be performed at all.

Maintenance:

• planned (according to the results of maintenance, according to the repair schedules)
• not planned (by technical condition)

Medium repair:

• disassembly of individual components for inspection, cleaning of parts and elimination of detected defects
• replacement of wear parts and components that do not ensure the normal operation of the equipment until the next overhaul

Medium repairs are carried out no more than once a year.

Overhaul:

• planned (according to repair schedules)
• unplanned (at the request of units, based on incidents and accidents)

Depending on the importance of equipment in the process of repair can be carried out in the following forms:

• regulated repair, which is planned and carried out within the time limits strictly established by the repair standards
• repair according to the technical condition (after the inspection method), the terms of which are established depending on the technical condition of the equipment, determined during the periodic maintenance
• repair work, which is performed after the equipment has completed the number of hours specified in its manufacturer’s documentation
• in one or another combination all of the above types of repair

For proper planning of maintenance and repairs, the department responsible for them must have all the necessary information: the structure of the repair cycle, the criteria for putting the product on maintenance and repair, etc. Therefore, in accordance with GOST 15.601-98 (valid in Ukraine), for each type of product, an appropriate set of documents should be developed, containing without fail:

• the structure of the repair cycle (types and frequency of maintenance and repairs) and the number of repair cycles for the service life of the product
• the amount of planned maintenance and repairs; criteria for putting the product on maintenance and repair
• typical product failures and methods to restore its performance
• allowed changes in product specifications after repair
• nomenclature and number of spare parts for maintenance and repair
• a system for collecting and processing information on failures, damage, duration, labor intensity and cost of planned and unplanned maintenance and repairs