Contents
- Corrective Maintenance: the beginning of the journey
- Preventive Maintenance: the first evolution
- Problems due to Preventive excess
- In some cases, the application of preventive maintenance may not be so strategic because it generates an excess of preventive maintenance due to the possible causes:
- The evolution from preventive to predictive maintenance
- What does predictive maintenance look like in practice?
- How is predictive maintenance transforming industries?
- Conclusion
Corrective Maintenance: the beginning of the journey
Corrective maintenance is the simplest and, historically, the most common approach. It occurs after equipment or system failure. This type of maintenance was widely used in early industrialization, when systems were less complex and failures did not have the same impact.
Its overall goal is to restore equipment operation after a failure, which can cause its cost to be elevated due to unplanned downtime and the cost of repairing and replacing parts.
Because their actions are reactive to failure, the biggest risk lies in the unpredictability of failure, which can result in extended downtime and additional costs.
While corrective maintenance has been widely used in the past, its reliance on unexpected failures makes it a less ideal approach in modern environments where competitiveness and cost reduction are priorities.
Over time, it was realized that the corrective approach was not the most efficient, especially in terms of cost and time. Thus, preventive maintenance emerged, which involves scheduled interventions based on the time or amount of use of assets.
Preventive Maintenance: the first evolution
Preventive maintenance involves a set of techniques that are applied in companies, so that equipment is supervised, checked, and possible corrections or replacements are made. Thus, problems are avoided that cause equipment not to perform its function.
It is scheduled to occur from time to time, and it is important that the responsible department has a review schedule. The periodicity must be defined by engineers and maintenance technicians, based on several factors, such as the amount of time that a particular piece of equipment is used or following the manufacturer’s own indications.
Problems due to Preventive excess
In some cases, the application of preventive maintenance may not be so strategic because it generates an excess of preventive maintenance due to the possible causes:
- When thinking only of preventive, discarding the hypothesis of applying other types of maintenance;
- When you have a wrong view of applying preventive maintenance without considering the Cost-Benefit ratio;
- When a shorter periodicity is adopted than that recommended by the manufacturer itself;
- When predictive techniques are not applied.
An excess of preventive maintenance directly interferes with equipment availability, reliability, and cost optimization, as it generates a demand for services during execution. When this demand exceeds what is necessary, equipment availability is impacted.
The availability and demand for services are inversely proportional quantities, that is, the greater the demand for services, the lower equipment availability, and vice versa.
In this scenario, a Maintenance manager may say that his main problem is the lack of labor, but if we analyze it from this perspective of excessive preventive maintenance, we can see that the main problem is, in fact, the excess demand for services, caused by one of the factors that led to an excess of preventive maintenance.
If we consider the problem as being only the lack of labor in the sector, the simplest but most expensive solution would be to hire more staff. When analyzing the perspective of the demand generated for services and focusing on an increase in equipment availability, the solution follows a different direction, which is the adoption of predictive maintenance.
Despite the necessary initial investment, this type of maintenance represents an intriguing cost-benefit for the company in the medium and long term and is one step ahead of preventive maintenance.
Although preventive maintenance has been a great advance over corrective maintenance, it does not consider the actual operating conditions of the equipment. In some cases, component replacements can still be performed before they actually show signs of failure, generating unnecessary costs.
The evolution from preventive to predictive maintenance
Predictive maintenance represents the third and most advanced stage in the evolution of maintenance methods. Unlike preventive maintenance, predictive maintenance uses real-time, real-time data to predict future failures. It relies on technologies such as sensors, data analytics, artificial intelligence, and machine learning algorithms to detect patterns of asset behavior and identify conditions that indicate impending failures.
One of the great paradigm shifts in maintenance occurs precisely when predictive is adopted, in addition to preventive maintenance. In this scenario, the criterion for performing maintenance is no longer just a certain time interval, and the equipment starts to operate up to a pre-established limit based on measurement parameters. In this way, operational continuity is prioritized without unnecessary interventions and downtimes.
Unlike preventive maintenance, predictive maintenance analyzes all equipment without distinction, even those that do not present any change that demonstrates the wear of a part or other problems. Its realization is scheduled according to a set of variables that will be analyzed. When there is a deviation in the variable, it is the appropriate time to perform predictive maintenance.
In this case, it has the help of instruments that measure variables such as pressure, temperature, vibration, voltage, and electric current, among others. The systematic verification of these variables enables the analysis of trends in equipment operation and the prediction of potential failures and defects.
The big issue here is not to replace preventive with predictive, but to evolve the practices adopted in the company to predictive techniques, maintaining the application of other types of maintenance depending on the situation.
Taking this into account, there are some situations in which preventive maintenance can be preferentially adopted, such as:
- When it is not possible to adopt predictive maintenance;
- In critical situations and equipment, which involve personal safety issues or risks to the environment;
- In continuous operation systems;
- By opportunity in difficult-to-interrupt equipment that is already stopped.
What does predictive maintenance look like in practice?
On a day-to-day basis, for those who do not have a tool to automate maintenance control, duplicate or concurrent maintenance is usually a schedule problem, which makes us waste time in scheduling and performing services. Other times they are also a cost problem.
Imagine that preventive maintenance was advanced by 2 weeks by a technician in the execution of another activity, in a planned corrective way, or even by a production opportunity. In order for us to be able to verify this execution and reschedule all subsequent preventive measures, there will be hours of analysis of the schedule. In addition, some perishable materials may have been requested and will have to be relocated to other services, or even will have to be discarded, generating losses, among other problems, on a daily basis.
With the adoption of software for maintenance control, this is automatically solved, since the next performances, if there is competition between the schedules, will only be generated at the end of the current activity on the correct date.
For example, let’s suppose that there is an equipment associated with a maintenance plan through cumulative scheduling with a limit of 1000 hours between each maintenance, and this same equipment is associated with the same plan through periodic scheduling every 7 days.
In this case, the same plan was associated with the same equipment, but on different schedules. Consequently, the system must generate W.O.s every 7 days (periodic) or every time the cumulative collection reaches the limit of 1000 hours (cumulative). Therefore, suppose the limit of 1000 hours is reached. The system will generate the work order (W.O.) normally and as long as it is not closed, no other periodic W.O. with this plan will be generated.
When closing this W.O., which was generated by the cumulative schedule, the last maintenance date will be updated both in the periodic and cumulative schedules and also in any other schedule in which this plan is associated with this equipment.
How is predictive maintenance transforming industries?
The adoption of predictive maintenance has been accelerated and strongly sought after by the increasing availability of sensor technologies, big data, and artificial intelligence. With sensors installed in critical equipment, it is possible to monitor the operational state of systems in real time, detect small anomalies, and predict when an asset is about to fail.
This approach reduces unplanned downtime and improves operational efficiency significantly. In addition, Industry 4.0 and the Internet of Things (IoT) have been driving factors for predictive maintenance.
The connectivity of the devices and the ability to collect large volumes of data make failure prediction more accurate and effective. Data analytics platforms can identify complex patterns and predict with great accuracy when a component may fail, allowing businesses to plan interventions in advance.
Conclusion
Correctly controlling the various types of maintenance that must be done on each piece of equipment is challenging. In an attempt to maintain a good job, there are companies that use several spreadsheets, but this method is not efficient. Regardless of the method adopted by the company, the goal of a manager is to make the equipment available as much as possible.
It is worth remembering that the adoption of a tool to optimize the organization will only bring results as the new culture is internalized in the company. It is important that it is clear to everyone which are the most effective types of maintenance and in which situations the applicability of each of them is most indicated.
We hope that so far we have contributed with valid tips for your day-to-day maintenance! Do you have more questions? Talk to us and understand how our software can be used in the most diverse types of maintenance.
