In the fast-paced time of edge computing, machine learning and artificial intelligence, the industrial sector is constantly exposed to new maintenance trends. The evolution of maintenance routines is unsparingly reshaping the industrial world with one main objective: to impact plant’s profitability in the best possible way depending on company’s budget, size and industry. 

And even though some business owners have forgotten reactive and corrective interventions long ago and are continuously investing in new equipment to follow predictive and even prescriptive trends, others are still struggling to establish timely scheduled preventive plans. The decision which maintenance approach to follow is strictly individual and depends a lot on the company’s financial capability, ability and culture. Nowadays there are 5 common maintenance types and each of them features certain advantages and disadvantages. 

1. The Corrective / Reactive Maintenance Approach

Corrective doesn’t replace reactive actions, but they are often put together because of their “unplanned, sporadic” nature and their objective to isolate and rectify a fault so that the failed equipment, machine, or system can be restored to its normal operable state. Corrective maintenance is carried out after failure detection, whilst reactive maintenance is performed after a breakdown so an asset can perform its intended function. The main advantages of this type of maintenance are the low short-term costs and the minimal planning required. However, in the long term, corrective and reactive maintenance actions result in unplanned additional costs, production delay and asset’s lifetime decrease. Therefore, this strategy is recommended for equipment which importance is very low and has no effect on production failures. This means that if a certain piece of equipment requires a higher investment for preventive maintenance than the costs needed for repair in case of failure, then corrective maintenance is the best solution.

2. Preventive Maintenance

By performing periodic maintenance check-ups, this timely based approach prevents machine failures before they occur. Preventive maintenance keeps assets more efficient and allows them to operate longer, avoiding unforeseen breakdowns in the production line. Even though preventive maintenance might seem at the beginning costly and time-consuming, it pays back by reducing the number of major breakdowns as well as the equipment’s downtime. Some professionals are blaming this approach for its “over-maintenance”, since sometimes equipment might not need to be checked as often as planned. In this case, the maintenance manager can simply adapt the schedule accordingly.On the one hand, preventive maintenance can be mandatory, defined in the contract, law or by any regulation. For example, the law requires the inspection and maintenance of certain machines. These machines must therefore be inspected and maintained. Client insurance companies generally require mandatory preventive maintenance.On the other hand, discretionary preventive maintenance is not a mandatory activity and relies on profits and losses and the company freely decides when to conduct preventive maintenance. Fault prevention is irreplaceable when chasing production deadlines and tight schedules. Preventive maintenance is used to maximize assets’ useful life and minimize costs by reducing reactive maintenance actions through the performance of regular inspections, lubrication, cleaning, oil changes, adjustments, repairs, and partial or complete replacement of periodically scheduled parts. In order to make fault detection easier and faster, the complete understanding of failures and their cause is essential. Keeping this in mind, professionals can use the right tools with the right frequency without spending too much time and efforts.

3. Predictive Maintenance 

Predictive maintenance is a condition-based process, forecasting when an equipment failure can occur and warning the maintenance manager. This is achieved through monitoring the condition of the equipment and performing maintenance in advance. Some examples of equipment monitoring methods include: 

• Vibration analysis: vibrations can detect machine failures and determine equipment status to schedule maintenance.
• Infrared thermography: infrared cameras can detect if a piece of equipment has an unusually high temperature.
• Acoustic analysis: this analysis is performed using sonic or ultrasonic tests to detect liquid or gas leaks.
• Analysis of the oil: by analyzing the oil condition, we can see the particle size and thus know the state of the equipment.

In the context of digitalization and the Internet of Things (IoT), a lot has been said, done and improved in the field of predictive maintenance routines recently. Banned by many business owners only a year ago because of its high costs, predictive maintenance is about to become largely spread since many producers launched sensors at affordable prices. Furthermore, when predictive maintenance is working effectively as a maintenance strategy, then it is only performed on machines when required and it brings several cost savings by: 

• minimizing the time, the equipment is being maintained, 
• minimizing production hours lost to maintenance and 
• minimizing cost for spare parts and supplies. 

However, many of the condition-monitoring techniques still remain expensive and require additional workforce. 

4. Reliability-Centered Maintenance

The reliability-centered maintenance approach is a corporate-level maintenance strategy aiming at optimizing the maintenance program of a company or facility by maintaining the function of the system and recognizing the failure that affects the function of the system. The result of a successful RCM program is the definition and implementation of a specific maintenance strategy on the most critical assets of the facility. Cost-effective maintenance techniques can be thus identified and later on adopted to improve the reliability of the facility as a whole.And even though RCM (reliability-centered maintenance) does not really consider additional costs of ownership, implementing it undoubtedly increases equipment availability, and reduces maintenance and resource costs.

5. Prescriptive Maintenance

Prescriptive analytics are at the heart of prescriptive maintenance, which is for now the last level in the evolution of all known maintenance routines. Compared to predictive practices, instead of only predicting a failure, predictive maintenance is “prescribing” an outcome-focused behaviour for operations and maintenance based on the prescriptive analytics. It is important to mention that this type of maintenance is still in its infancy but many ingenious business owners are considering its potential to become the next big thing in reliability and maintenance best practice.However, even for organizations with well-established predictive maintenance routines, the leap towards prescriptive programs may still be difficult mainly because of the cost for new hardware and software and workforce, regulations on specific machines, the company’s culture and the management’s long-held beliefs.

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Even though predictive and prescriptive approaches have a huge potential and are rather the strategies corresponding the most to today’s digitalization trends, preventive maintenance remains the mostly spread maintenance program. This is mainly due to its largely appreciated advantages as: 

Reduced Production Downtime

When the problem occurs, it can be quickly resolved because the worker knows what to do and what spare part to replace, which will reduce the time needed to detect the problem.

Reduced Breakdowns

With preventive maintenance, the equipment will be regularly maintained within the given deadlines so that it is in the best conditions.

Cost Savings

Preventive maintenance reduces the frequency of breakdowns, which means reduced production stops and more financial benefits. 

Improved Productivity

Reduced equipment downtime results in increased plant’s productivity and machine availability.

Eliminate Ambiguity in Maintenance Tasks

Preventive maintenance reduces the risk of unnecessary repairs and creates a system to use the right tool for the right task.

Extended Equipment Life

Preventive maintenance improves equipment performance and increases product quality because machines are well maintained, and equipment is performing well.

Improved Customer Service and Reputation

A successful preventive maintenance program contributes to reliable delivery time, good production quality and thus improves the reputation of the company.

Reduced Energy Waste

Preventive maintenance lowers the cost of energy because well-maintained equipment generally requires less electricity or fuel to operate.

Improved Facility Security

Equipment breakdowns can have disastrous consequences. Properly maintained equipment will improve the safety of workers, as well as of those working around the equipment, so that well-maintained equipment create a safer work environment.

The most important thing to remember when looking for the right maintenance strategy is the problem that you have to solve. This will help you find and implement the right solution and finally sustain winning results.

Predictive and prescriptive maintenance strategies have a powerful potential, but their implementation might be difficult if you don’t have an established successful preventive maintenance program yet. After all, there is no wrong or right approach to maintenance; you simply must choose what’s feasible for your company in order to achieve the best possible results. 

Ralitsa Peycheva
technical content manager at
Mobility Work