| Term | Abbreviation | Definition |
| 1. General concepts |
| 1.1. Maintenance | MA | Set of technical measures aimed at maintaining machinery in good technical condition when preparing for use, during use, storage and transportation.
NOTE: The content includes technical inspection, cleaning, lubrication, tightening and adjustment. |
| 1.2. Repair | RP | Set of technical measures aimed at maintaining and restoring the working capacity or good technical condition of machinery. |
| 1.3. Machinery maintenance and repair system | | A set of unified regulations and guidelines to determine the form of organization, content and order of implementation of planned maintenance and repair work to maintain the working capacity and good technical condition of machinery throughout the service life under certain operating conditions. |
| 1.4. Preventive planned maintenance and repair system | | systemA maintenance and repair system that is carried out according to a predetermined plan to prevent failures throughout the machinery’s usage process. |
| 1.5. Repairability | | The structural characteristic of machinery expressed in the ability to predict, easily detect and remedy failures through maintenance and repair. |
| 1.6. Technical condition of machinery | | The set of technical states of machinery that have changed during use (storage, transportation) at a certain point in time, assessed by the technical parameters recorded in the machinery’s technical documentation. |
| 1.7. Technical diagnosis | TD | A process of determining the technical condition of machinery without disassembly. |
| 1.8. Part | | A part of machinery that cannot be further divided by disassembly processes. |
| 1.9. Assembly | | A part of machinery that is assembled from several different parts. |
| 1.10. Unit | | A part of machinery that is assembled from several parts and assemblies to perform a certain complete function of the machinery. |
| 1.11. Spare parts | | Parts, assemblies, etc. that are stored to replace corresponding parts of machinery in use in order to maintain the working capacity and good technical condition of the machinery. |
| 1.12. Machinery tool set | | A set of spare parts, tools and necessary materials accompanying new machinery based on the nature and characteristics of use for maintenance and repair. |
| 2. Maintenance |
| 2.1. Periodic maintenance | | Maintenance according to a planned sequence, in accordance with TCVN 4204. |
| 2.2. Shift maintenance | | Maintenance for each working shift of the machinery.
NOTE: It can be performed before, during or after each working shift. |
| 2.3. Maintenance during storage | | Maintenance in the stages of preparation for storage, storage and after storage. |
| 2.4. Maintenance during transportation | | Maintenance in the stages of preparation for transportation, transportation and after transportation. |
| 2.5. Maintenance level | | The division of maintenance content according to the volume and complexity of work for planned maintenance in accordance with TCVN 4204.
NOTE: Periodic maintenance is divided into 3 levels: PM1, PM2, PM3 |
| 2.6. Maintenance interval | | The specified number of working hours of machinery between two consecutive maintenance sessions of the same level. |
| 2.7. Maintenance cycle | | The shortest time interval (counted in working hours) that repeats many times. Within that time interval, the maintenance levels are performed in a certain order according to TCVN 4204. |
| 2.8. Time for one maintenance session | | The time required for one machinery maintenance session (counted in working hours). |
| 2.9. Total maintenance time | | The total time required (counted in working days) for maintenance within a certain period of machinery use.
NOTE: The waiting time for machinery to enter maintenance is not included in this time. |
| 2.10. Maintenance time coefficient | | The ratio between the total maintenance time and the number of working hours of machinery within the same period of use. |
| 2.11. Labor consumption for one maintenance session | | The amount of labor required to perform one machinery maintenance session (counted in man-hours). |
| 2.12. Total maintenance labor consumption | | The total amount of labor required for maintenance (counted in man-hours) within a certain period of machinery use. |
| 2.13. Average maintenance labor consumption | | The average maintenance labor consumption (counted in man-hours) for one machine (or maintenance level) within a certain period of machinery use. |
| 2.14. Maintenance labor consumption per working hour | | The ratio between the average maintenance labor consumption and the average number of working hours of machinery within a certain period of use. |
| 2.15. Maintenance labor cost | | The necessary costs (counted in monetary terms) for one machinery maintenance session. |
| 2.16. Total maintenance cost | | All the necessary costs (counted in monetary terms) for maintenance within a certain period of machinery use. |
| 2.17. Average maintenance cost | | The average maintenance cost for one machine (one maintenance level) within a certain period of machinery use (counted in monetary terms). |
| 2.18. Maintenance cost per machine working hour | | The ratio between the average maintenance cost and the average number of working hours within the same period of machinery use. |
| 2.19. Probability of maintenance within a given time | | The possibility of the occurrence of the number of machinery maintenance sessions with the actual maintenance time not exceeding the predetermined time. |
| 3. Repair |
| 3.1. Periodic repair | | Repair according to a predetermined plan, in accordance with TCVN 4204. |
| 3.2. Unscheduled repair | | Repair not according to a predetermined plan, to remedy unusual failures of machinery. |
| 3.3. Current repair | CR | Repair of machinery performed during the period of use by replacing, restoring and adjusting parts to ensure the working capacity of the machinery between two overhauls. |
| 3.4. Overhaul | OH | Repair aimed at restoring the good technical condition of machinery (like or almost like new machinery) by completely disassembling to replace or restore parts (assemblies, units…) including the base parts of the machinery such as beds, frames, testing and adjusting parts and the whole machinery. |
| 3.5. Repair level | | The division of repair content according to the volume and complexity of work for machinery repair according to a certain plan in accordance with TCVN 4204.
NOTE: Periodic repair is divided into 2 levels:
– Current repair;
– Overhaul. |
| 3.6. Interchangeable repair | | A method of repairing machinery by replacing damaged parts (assemblies, units…) with corresponding new or good technical condition parts (assemblies, units…) from other machines of the same type. |
| 3.7. Non-interchangeable repair | | A method of repairing machinery by reinstalling the parts (assemblies, units…) that have been removed for restoration into that machinery. |
| 3.8. Assembly-unit replacement repair | | A form of interchangeable repair in which the damaged assemblies (units) of the machinery are replaced by assemblies (units) taken from the unit reserve stock. |
| 3.9. Unit reserve stock | | The amount of new or restored assemblies (units) necessary to be stored for machinery repair using the assembly-unit replacement method. NOTE: The required number of units (assemblies) is calculated according to the following formula:
Where:
– N: Number of assemblies, units needed to be reserved (pieces)
– C: Number of identical assemblies, units on 1 machine (pieces)
– M: Number of machines of the same type
– Tkh: Planned working time of 1 machine/year
– ts: Usage time of the assembly, unit
– K: Reserve coefficient: 1.1 to 1.3 |
| 3.10. Time between repairs | | The time interval counted in actual working hours between two consecutive repairs of the same level. |
| 3.11. Repair interval | | The number of working hours of machinery specified between two consecutive repairs of the same level. |
| 3.12. Repair cycle | | The shortest time interval repeating many times (counted in machinery working hours). Within that time interval, the maintenance and repair levels of machinery are performed in a certain order according to TCVN 4204. |
| 3.13. Repair cycle structure | | Includes the number, interval and order of implementation of maintenance and repair levels in a machinery repair cycle. |
| 3.14. Time for one repair session | | The time required for one machinery repair session (counted in working days).
NOTE: The waiting time for machinery to enter repair is not included in the repair time. |
| 3.15. Total repair time | | The total time required (counted in working days) for repair within a certain period of machinery use. |
| 3.16. Repair time coefficient | | The ratio between the total repair time and the number of working hours of machinery within the same period of use. |
| 3.17. Labor consumption for one repair session | | The amount of labor required for one machinery repair session (counted in man-hours). |
| 3.18. Total repair labor consumption | | The total amount of labor required (counted in man-hours) for repair within a certain period of machinery use. |
| 3.19. Average repair labor consumption | | The average repair labor consumption (counted in man-hours) for one machine (or for one repair level) within a certain period of use.
NOTE: Calculated for a group of machines used and repaired under different conditions. |
| 3.20. Repair labor consumption per machine working hour | | The ratio of average repair labor consumption to the average number of working hours of machinery within the same period of use. |
| 3.21. Cost for one repair session | | The necessary costs for one machinery repair session (counted in monetary terms). |
| 3.22. Total repair cost | | All the necessary costs (counted in monetary terms) for repair within a certain period of machinery use. |
| 3.23. Average repair cost | | The average repair cost (counted in monetary terms) for one machine (or for one repair level) within a certain period of use.
NOTE: Calculated for a group of machines used and repaired under different conditions. |
| 3.24. Repair cost per machine working hour | | The ratio between the average repair cost and the average number of working hours within the same period of machinery use. |
| 3.25. Probability of repair within a given time | | The possibility of the occurrence of the number of machinery repair sessions with the actual repair time not exceeding the predetermined time. |
| 3.26. Warranty period | | The time period starting from the receipt of machinery after overhaul to the specified time point for each type of machinery. Within that time period, the repairing party must comply with the regulations to fulfill all requirements of the machinery managing party, if the machinery managing party has used (stored, transported) the machinery according to current standards. |
| 3.27. Warranted working time | | The time period specified by the number of machinery working hours starting from the receipt of machinery after overhaul. Within that time period, the repairing party must comply with the regulations to fulfill all requirements of the machinery managing party, if the machinery managing party has used (stored, transported) the machinery according to current standards. |
| 3.28. Annual maintenance and repair plan | | A production plan established by the units directly managing the machinery in accordance with the guidance documents, to determine the quantity and timing of implementation of machinery maintenance and repair levels during the year. |
| 3.29. Monthly maintenance and repair plan chart | | A production plan established by the units directly managing the machinery in accordance with the guidance documents, to determine the timing of implementation of machinery maintenance and repair levels during the month. |
