CORRECTIVE MAINTENANCE

 2.1. CORRECTIVE MAINTENANCE   

By Aleksandar Pudar

Technical Superintendent and Planned Maintenance Supervisor Reederei Nord BV

Co-founder of "Out of Box Maritime Thinker Blog" and Founder of Naro Consilium Group

There are three categories of maintenance tasks: breakdown, corrective, and preventive. The main contrast among these categories lies in the timing of their execution.

Breakdown maintenance deals with repairing the equipment only after it has stopped functioning i.e. experienced a catastrophic failure. On the other hand, preventive maintenance is carried out before any problem is detected,i.e. even if t is not necessary, while corrective maintenance is scheduled to address specific issues identified in onboard machinery/equipment.

Ideally, a thorough maintenance program should combine all three categories. However, unfortunately, many owners and vessel operators rely heavily on breakdown maintenance to keep their critical machinery /equipment/systems operational.

2.1.1 BREAKDOWN MAINTENANCE

In the maritime industry, the focus on the operating condition of critical machinery, equipment, or systems is crucial. Reactive maintenance programs solely concerned with returning a machine or system to service as quickly as possible are ineffective and extremely expensive.

Breakdown maintenance, in particular, has two primary factors contributing to high maintenance costs: poor planning and incomplete repair. Due to time constraints imposed by production and vessel management, most repairs in breakdown maintenance are poorly planned, resulting in minimal manpower utilisation and ineffective use of maintenance resources. Typically, reactive maintenance will cost three to four times more than the same repair when it is well-planned.

The second limitation of breakdown maintenance in the maritime industry is that it focuses on repairing obvious failure symptoms rather than addressing the root cause. For example, a bearing failure may cause a critical machine to seize and stop. The bearing is replaced ( sometimes quickly, sometimes with the vessel being off-hire) in breakdown maintenance, and the machine is returned to service.

However, there is no attempt to identify the primary factor that led to the bearing failure or to stop it from happening again. As a result, the machinery, equipment, or system becomes significantly less reliable, increasing the frequency of repairs and significantly raising maintenance costs.

To overcome these limitations, a comprehensive maintenance program that includes preventive and corrective maintenance and breakdown maintenance should be implemented. Preventive maintenance involves performing routine inspections and maintenance tasks before a problem occurs, while corrective maintenance is scheduled to address specific issues identified in-vessel systems. Addressing the root cause of failures and implementing a proactive maintenance approach can significantly improve the reliability of critical machinery, equipment, and systems while minimising maintenance costs.

2.1.2 PREVENTIVE MAINTENANCE

 

Preventive maintenance is essential in the marine environment, especially in the operation of vessels. It is a proactive approach to maintenance that involves performing regular maintenance tasks on critical equipment, machinery, and systems to prevent breakdowns, reduce downtime, and extend their lifespan. The goal is to identify and address potential problems before they cause equipment failure, which can lead to costly repairs and off-hire losses and pose a risk to the safety of the vessel, crew, and environment.

Preventive maintenance tasks on a vessel include regular inspections, cleaning, lubrication, calibration, and replacement of parts or components. These tasks are scheduled based on manufacturer recommendations, industry standards, and the specific operating conditions of the vessel.

Implementing a comprehensive preventive maintenance program for a tanker vessel offers several benefits, including increased reliability, improved safety, a longer lifespan of equipment, and cost savings. Regular maintenance can help identify and address potential issues before they become significant problems, improving equipment reliability and reducing downtime. It can also help identify and mitigate safety hazards, reducing the risk of accidents or injuries. Proper maintenance can extend the lifespan of equipment, reducing the need for premature replacement and lowering overall costs. Addressing minor issues before they become significant problems can help reduce repair and replacement costs.

Overall, preventive maintenance is essential for any vessel operator that wants to ensure safe and efficient cargo transportation, protect the marine environment, and comply with international regulations. By implementing a comprehensive preventive maintenance program, vessel operators can improve equipment reliability, increase safety, and reduce costs, increasing efficiency and profitability.

 

2.1.3 CORRECTIVE MAINTENANCE

 

Corrective maintenance is an essential part of maintenance practices in the marine industry. Corrective maintenance involves addressing equipment failures or malfunctions that occur unexpectedly or during routine inspections. Onboard vessels, corrective maintenance is necessary to address equipment failures that can impact the safety of the vessel, crew, and cargo, including issues with propulsion systems, steering gear, cargo handling equipment, and safety systems. Therefore, it is crucial to have a well-established corrective maintenance program to lessen the effects of equipment failures; this program should include protocols for reporting and addressing equipment problems and backup plans for handling emergencies.

In addition, a proactive approach to maintenance management is necessary to eliminate breakdowns, deviations from optimum operating conditions, and unnecessary repairs to optimise the effectiveness of all critical plant systems. The fundamental objective of this approach is to correct existing problems and prevent equipment failures before they occur.

Corrective maintenance is a subset of a comprehensive preventive maintenance program, focusing on regular, planned tasks to maintain all critical plant machinery and systems in optimum operating conditions. Maintenance effectiveness is judged on the life-cycle costs of critical plant machinery, equipment, and systems, not how quickly a broken machine can be returned to service. The principal concept of corrective maintenance is that proper, complete repairs of all incipient problems are made as needed. All repairs are well planned, implemented by adequately trained craftsmen, and verified before the machine or system is returned to service.

In addition to addressing equipment failures, corrective maintenance can involve modifying or upgrading equipment or systems to improve performance or comply with new regulations or standards. Corrective maintenance is essential for maintaining onboard tanker vessels' safety and efficiency. Owners and operators of vessels are able to reduce downtime, cut repair costs, and ensure the safety of the ship, its crew, and its cargo by setting up an effective corrective maintenance program.

2.1.4. PREREQUISITES OF CORRECTIVE MAINTENANCE

Particular prerequisites must be in place for corrective maintenance to be effectively implemented. These prerequisites are essential for ensuring that corrective maintenance activities are carried out smoothly and efficiently.

2.1.4.1 ACCURATE IDENTIFICATION OF DEVELOPING ISSUES

Accurately identifying developing issues is crucial for preventive and corrective maintenance programs in the marine industry. The first requirement of corrective maintenance is a comprehensive predictive maintenance program that can anticipate maintenance requirements and accurately identify the root cause of all incipient problems. Corrective actions cannot be adequately planned or scheduled without this ability, leading to potential breakdowns and costly downtime.

2.1.4.2 PLANNING

In the marine industry, preventive and corrective maintenance programs must accurately identify developing issues and anticipate maintenance requirements to prevent breakdowns. A comprehensive predictive maintenance program that can identify the root cause of all incipient problems is essential for effective corrective maintenance planning and scheduling, which minimises costs and interruptions (off-hire). Well-trained planners, a functional maintenance database, and comprehensive repair procedures for each machine or system on board the vessel are essential for the proper planning and execution of maintenance activities.

2.1.4.2.1 TRAINED MAINTENANCE PLANNERS

To minimise off-hire and any schedule interruptions and costs, well-trained maintenance planners must be able to plan and schedule corrective repairs and maintenance activities effectively. However, in the marine industry, maintenance planning may not always be a full-time job, and some planners may lack the required knowledge and skills. Hence, providing appropriate training is crucial to ensure that every planner possesses the necessary skills to properly plan and execute maintenance and repair tasks.

2.1.4.2.2 MAINTENANCE HISTORY DATABASE

It is crucial to have maintenance planners that have the appropriate training and abilities to effectively organise repair and maintenance work in the maritime industry or the portion of the industry that handles vessel maintenance. Additionally, accurate maintenance history is crucial for planning efficient repairs. A maintenance planner must know the standard mean-time-to-repair for every recurring maintenance task and be familiar with the specific tools, repair parts, and skilled craftsmen required for each task. Without this information, planning an effective repair is impossible. Therefore, a comprehensive maintenance database that includes actual mean-time-to-repair, standard repair procedures, and other important information is necessary for proper maintenance planning in the maritime industry.

2.1.4.3 PROPER REPAIR PROCEDURES

In the maritime industry, it is crucial to ensure that repairs are completed thoroughly and adequately, as poor maintenance or repair practices can cause more damage to critical vessel machinery than the original failure. Corrective maintenance requires complete repair of each developing issue, which can be achieved by craftsmen who have the necessary skills, repair parts, and tools to restore the vessel to its original condition. However, a growing number of maintenance personnel lack the necessary skills to maintain or repair vessel equipment and systems, including bearing installation, machine alignment, and balancing rotating equipment. Therefore, continuous training programs that provide minimum craft skills required to support vessel operations are necessary, and these training programs should include a means of verifying and periodically refreshing these skills. In order to reduce excessive downtime and repair expenses, appropriate repair processes are essential for ensuring that repairs are carried out effectively and that vessels are maintained in optimal working conditions.

2.1.4.3.1 STANDARD MAINTENANCE PROCEDURES

In the maritime industry, standard maintenance procedures are crucial to ensuring the reliability and safety of vessels. The Oil Companies International Marine Forum (OCIMF) has developed guidelines for standard maintenance procedures for the marine industry, which cover a wide range of topics, including engine maintenance, electrical systems, and safety equipment. These guidelines emphasise the importance of regular inspections, testing, and maintenance of critical equipment to identify and prevent issues before they become significant problems.

Engineering reliability also stresses the importance of standard maintenance procedures in ensuring the optimal performance of equipment and systems. Proper maintenance procedures should be well-defined and documented, outlining the correct methods and tools required for each task and any necessary safety concerns or repair parts. The craftsmen responsible for the maintenance or repair should not be required to search for additional information to complete the task.

In addition, allowing sufficient time for proper maintenance is crucial to reducing the frequency of breakdown repairs; this requires a shift in management philosophy to prioritise maintenance and permit adequate time for all critical systems to undergo preventive or corrective maintenance. With proper maintenance and standard procedures, machinery can be maintained optimally, leading to less downtime and a safer and more efficient operation.

2.1.4.4 APPROPRIATE OPPORTUNITY/TIME TO REPAIR

To minimise any downtime or disruptions to vessel business, when maintaining vessels, it is essential to provide enough time for repairs to be finished. Adequate time must be allocated for proper maintenance, and management must prioritise providing sufficient time for critical systems to be adequately maintained.; this change in management philosophy will ultimately reduce the downtime required to maintain critical equipment and systems. Based on the severity and impact of the problem, the best opportunity or time to repair must be chosen. Careful preparation must be done to guarantee that all necessary resources, such as tools, repair parts, and skilled labour, are accessible to carry out the repair promptly and efficiently.

2.1.4.5 REPAIR VERIFICATION

In the context of a seagoing vessel and the maritime industry generally, verifying all corrective repairs or rebuilds is essential. This verification process helps ensure that the repair was carried out correctly and that any possible issues that could compromise the vessel's safety or operational capabilities have been addressed.

2.1.4.6 ROLE OF CORRECTIVE MAINTENANCE

Corrective maintenance is essential in the marine sector to preserve the ship's integrity and its systems. However, the ultimate goal of any maintenance program should be to eliminate the need for corrective maintenance by putting in place a strong preventive maintenance program; this would help to reduce the frequency of corrective maintenance actions and eliminate machine, equipment, and system problems that require corrective actions, thereby enhancing the overall reliability and safety of the vessel.

 

References & Bibliography:

 

1.        Mobley, R.K. (2014) Maintenance engineering handbook. 7th edn. New York: McGraw-Hill.

2.        Olley, J. (2023) "What is PPM (Planned Preventative Maintenance)?," www.fixflo.com. Tactile Limited, 20 February. Available at: https://www.fixflo.com/blog/what-is-ppm (Accessed: April 1, 2023).

 

 

Disclaimer:

Out of Box Maritime Thinker © by Narenta Gestio Consilium Group 2022 and Aleksandar Pudar assumes no responsibility or liability for any errors or omissions in the content of this paper. The information in this paper is provided on an "as is" basis with no guarantees of completeness, accuracy, usefulness, or timeliness or of the results obtained from using this information. The ideas and strategies should never be used without first assessing your company's situation or system or consulting a consultancy professional. The content of this paper is intended to be used and must be used for informational purposes only.