The role of the maintenance operator in advanced machine maintenance

The intensification of mechanization has led to the need to keep machines operationally available and maximize their useful life. This objective can only be achieved through an efficient maintenance strategy. This is necessary because it involves actions to ensure that a given machine, equipment or implement, herein treated as an asset, is preserved or restored so that it can remain in specific conditions and with the possibility of optimizing the process.

For rural properties managed as companies, currently, asset maintenance has become one of the foundations for increasing profits and gains; and has a major impact on planning.

Companies, in general, require an efficient maintenance process. This operation must be carried out with competence, creativity, flexibility, speed, a culture of change and, of course, with teamwork, as there is no room for maintenance without commitment and improvisation.

To achieve this, it is essential that the maintenance management process is effective and presents organized guidelines, so that the assets meet the planning, thus obtaining the return on investment. The guidelines must be prepared in a practical and objective way, meeting the needs, as well as making use of the different types of maintenance.

Types of maintenance

Maintenance operations currently have several implementation and performance modes. They are being used in industries, service provision sectors and in machines and implements used in the primary sector.

In the primary sector, not all operations planned in an industrial maintenance plan can be implemented. However, many techniques are used and provide gains. The maintenance sector is often asked about the withdrawal of assets from its operations, since, for many, the period invested in maintenance is a waste of time. However, it should be noted that maintenance, when planned in its various segments, will not generate a loss of productive time, but rather an investment in process improvement. In this context, some types of maintenance that can be used in rural areas will be described below.

Preventive or periodic maintenance

Preventive or periodic maintenance can be defined as actions aimed at predicting or eliminating failures or drops in the desired performance of an asset. Various tools and techniques are used to identify potential problems, such as periodic inspection. This requires the maintenance manager to know the equipment, its history and early failures, in order to understand the techniques through which it is possible to predict correction without hindering the progress of the process.

Preventive maintenance planning should include, at a minimum, lubrication actions so that assets can perform their functions as expected and designed. In addition, maintenance execution should adopt quality criteria, such as eliminating dirt and preventing contamination of lubricants. During this maintenance, the maintenance recommendations provided in the asset manual provided by the manufacturer must be followed.

Predictive maintenance

This type of maintenance involves monitoring the operating conditions of assets to detect signs of wear that may precede failures. Its nature goes beyond being a planned maintenance tool. This is because it offers the best results in monitoring asset performance. It makes it possible to reduce the number of production stops for maintenance, resulting in greater effective machine operating time and, consequently, increased production.

Predictive maintenance can be used in a variety of areas, as it not only measures the operating conditions of equipment and machines, but also allows for an effective assessment of the entire functional group. If used appropriately, it can identify many of the factors that limit operational efficiency.

However, even with all the data from preventive and predictive inspections, over the course of the asset's useful life the probability of a failure occurring between two maintenance operations increases, which then implies corrective action.

Corrective maintenance

Corrective maintenance involves actions to correct faults resulting from wear or deterioration. It involves repairing parts that have failed, broken or are performing worse than expected. It includes activities such as: repairs, alignments, balancing, replacing parts, adjusting component clearances, among others. This type of intervention involves high costs and wasted time. This can require longer periods to replace parts, rendering the machine inactive, in addition to reducing productivity and the quality of the process and product.

There is no way to completely eliminate corrective maintenance. However, each rural property must perform a historical analysis of its database and define the acceptable corrective maintenance index. Therefore, the fewer emergency corrective maintenance actions there are, the lower the cost involved in shutdowns.

MCC and MPT

The high costs involved in corrective maintenance and the need for a planned maintenance method gave rise to reliability-centered maintenance (RCM). This aims to work in conjunction with equipment availability and safety, without increasing expected costs. It is understood as a technique used to determine what should be done to ensure that equipment operates correctly. It seeks interaction and optimization between predictive and preventive maintenance. It also aims to assess the maintainability of equipment and identify critical points in order to, perhaps, subsequently improve the design of the machine.

Associated with this maintenance concept, centered on reliability, total productive maintenance (TPM) was developed, which also aims to reduce production costs. It aims to hold supervisors, operators and maintenance technicians accountable and unite them, in order to expand and facilitate the flow of information about the operation and maintenance of the asset.

In Total Productive Maintenance, operators develop inspection, lubrication and cleaning routines with the goal of increasing equipment efficiency. In this context, the maintenance operator emerges, a definition given to the operator who is capable of operating the machine and keeping it in operation, performing small maintenance services.

Maintainer operator

To implement the maintenance operator strategy through the relentless pursuit of loss reduction, it is essential to execute three basic principles presented by Paccola (2011), as we can see below.

Keeping equipment clean: Initially, external cleaning should be considered to observe leaks, gaps, cracks, smoke, dented parts or components. It is also important to investigate the sources of dirt to prevent leaks of possible contaminants. Keep the operating station clean, as a comfortable work environment stimulates work and boosts production.

Know the equipment: The relationship between the maintenance operator and the machine is important, since he needs to have in-depth knowledge of the asset so that he can obtain the best results from the operations performed. With knowledge of each of the equipment's characteristics, when carefully inspected, it is possible to distinguish what is normal from what is abnormal. In cases of abnormality, maintenance is carried out immediately, optimizing production without compromising the machine's useful life.

Inspection plans are important when carrying out maintenance, as they ensure that certain procedures are carried out as recommended by the manufacturer.

The interaction between the operator and the asset, in a constant cycle of identifying abnormalities and quickly resolving them, characterizes a gradual improvement in the assets. Furthermore, the operator is motivated to constantly seek training so that he can perform maintenance with quality.

It is worth noting that in this inspection process, communication between the operator and the maintenance/management sector must occur efficiently, preventing information from being lost. Control and recording are important factors for the success of the maintenance operator, as they allow the database to be kept up to date for information management.

If the system for recording abnormalities or services is not fully digital, it is important to use labels, cards or even a notebook, which must be filled out by the operators, containing: identification of the operator and asset, date, hour meter (when present), reporting the abnormalities and the time invested in the solution.

Perform minor repairs: Because the maintenance operator knows the machine, he/she performs small repairs. Often, the abnormalities are simple and require quick correction. If performed by the operator, it speeds up the operation and optimizes production. For this to be possible, the operator must be trained and qualified, have adequate tools and perform only the repairs and services that were defined in advance in a meeting with the person in charge. For the maintenance operator to be effective, the process must be structured, respecting the time required for each stage to evolve, as shown in Figure 1.

How to implement a system with a maintainer operator

There are factors that can facilitate the implementation of the maintainer operator strategy:

• Implement incentive systems for workers (usually financial).
• Train operators adequately until they reach the level of knowledge necessary to carry out maintenance.
• Monitor the operation during the initial phase of the process, because it involves a change in the behavior of operators and managers.

Once the implementation stages have been completed, the concept of a maintenance operator has recorded positive results, due to the interaction between maintenance and operation of the asset, as well as strengthening the team.

A maintenance program with this focus will only be successful if it moves from a failure management routine to a machine usage cycle management routine. Normally, the path starts from breakdown maintenance and moves on to planned maintenance and improvement maintenance, achieving the broader concept of asset management (Vieira, 2011).

*Per Gessieli Possebom, Catize Brandelero e Valmir Werner, from the Agricultural Machinery Testing Center (Nema) – CCR of the Federal University of Santa Maria (UFSM)