Preventive Maintenance for Sustainable Engineering in Shipping Company

Improvements in ship reliability for shipping companies are an important factor in surviving in global competition. Therefore, appropriate maintenance activities are required to increase the reliability of vessels. Selecting an effective maintenance strategy is necessary to minimize breakdowns. Continuous maintenance of facilities has a big impact on efforts to accelerate sustainable industrialization, which is one of the goals of sustainable development. This research intends to shorten the excessively long breakdown period of ships, which may take up to seven months to restore a ship’s body. Preventive maintenance methodology is utilized in this study, which complies with the operation for sustainable system engineering. The result of the research shows the mean time to repair and mean time before failure are still below decent standards (95%). Finally, ship body repairs should be carried out using reactive, preventive, and predictive maintenance procedures.


Introduction
The shipping industry in Indonesia witnessed fierce competition as companies vied for market share amidst a growing demand for maritime services.The competition gave rise to company operations in the fields of ship rental, transportation of goods, and material cargo.This activity allows continuous use of the ship, which impacts the potential breakdown of the vessel.Therefore, this can be anticipated by increasing ship reliability in operation through maintenance activities.The maintenance process, which must ensure the availability, reliability, and safety of equipment, has a key role in sustainable operations [11].Unfortunately, this activity required a long interval of time.One company even requires a maintenance time of up to 7 days.This time is considered too long, thereby reducing the company's work productivity.
A maintenance management strategy that can be implemented to reduce maintenance time is very much needed by shipping companies [1].They need an effective way to identify the length of time for ship body repairs.Maintenance engineering plays a pivotal role in sustainability engineering by optimizing and prolonging the lifespan of assets, reducing resource consumption, and minimizing environmental impact through efficient and eco-friendly practices.Apart from that, regular scheduling is needed to speed up ship body maintenance time.Designing other strategies for ship body maintenance can be done using the predictive maintenance method.Furthermore, efforts need to be made to monitor 1324 (2024) 012089 IOP Publishing doi:10.1088/1755-1315/1324/1/012089 2 the performance of companies that are experiencing difficulties due to not using digital systems in maintenance schedules and stocking ship body equipment.
This research aims to identify the problems faced by shipping companies related to the length of ship body repair time by implementing regular scheduling and speeding up ship body maintenance time using reactive maintenance and preventive maintenance methods.Furthermore, the company must be able to determine the design of other strategies for ship body maintenance using the predictive maintenance method.In the end, shipping companies can monitor the performance of companies that experience difficulties due to not using digital systems in maintenance schedules and shipping equipment stock by implementing the digital system concept.

Literature Review
Industrial enterprises seek to integrate environment into their strategy by conducting an innovative rationalization of the production which comply with sustainability concept [12].The role of maintenance has an important contribution to the development of those paradigms.Maintenance management involves overseeing and coordinating the planning, execution, and supervision of maintenance activities to ensure the reliable and efficient operation of assets and facilities.maintenance is a type of activity carried out to repair or maintain an object until it reaches the goal of being reused [2].Fishbone analysis, or Cause-effect Diagram (CED), is carried out by applying a fishbone diagram, which is used to determine the causes and consequences of damage to a component and is used as a systematic way to determine the occurrence of a problem [6].Maintenance carried out using reactive maintenance is a way of carrying out repairs by repairing damage from failures in an object or ship directly [6].
The aim of preventive maintenance is to minimize downtime based on the results obtained, maximize the value of availability, and reduce excessive expenditure when carrying out repairs.FMEA aims to be able to organize future for ship maintenance and determine the breakdown time that occurs [7].The damage level parameter, or severity (S), measures the level of danger; occurrence (O) measures the level of failure; and detection (D) measures the level of difficulty [7].The function analysis system technique (FAST) diagram is a diagram that applies a functional structure by providing a design for a service identified with the right questions [2].

Methodology
The research method carried out in this research uses four types of methods: the reactive maintenance method, the preventive maintenance method, predictive maintenance, failure mode effect analysis (FMEA), and the FAST diagram.This method is used to identify components that have serious damage, components that must be repaired directly, scheduled, and analyzed, reduce breakdown time, reduce company expenses, and determine the maximum operational time.Data collected through the interview process was carried out with questions in the Reactive Maintenance and Preventive Maintenance Methods section to get the right time when the ship was operating and being repaired.Questions for the questionnaire were carried out by obtaining data from Failure Mode Effect Analysis (FMEA), which was also used to obtain the cause of the problem using a Fishbone Diagram.After obtaining the data, a reactive maintenance process is carried out, which is used to obtain data on repairs carried out directly, and calculations of repair and operational time are carried out using the formulas of Mean Time to Repair (MTTR) and Mean Time Between Failure (MTBF) to determine breakdown time and correct operational time.Perform calculations using the availability formula to determine the average time used for repairs.The next calculation is carried out by calculating the Risk Priority Number (RPN), which makes it easier to group each ship body component needed for appropriate repair criteria.Next, a digital system concept was created using a FAST diagram to help check equipment scheduling and stock.After getting the results from the calculations and analysis, testing was carried out using the Minitab application to test data adequacy, normal, lognormal, exponential, and Weibull distributions.

Result and Discussion
The data collection carried out has obtained results from activities carried out during ship use and ship body repairs from January 2020 to December 2022.The determination of damage is analyzed using the Failure Mode and Effects Analysis (FMEA) method, which is used to determine the damage that occurs in every component of the ship's body.An analysis of the ship's body was obtained for seven components using the Failure Mode and Effects Analysis (FMEA) method to determine function, functional damage, description of damage, consequences of damage, and detection of damage.There are three descriptions of damage: type of damage, damage mechanism, and cause of damage.This implementation also needs to be ensured to find out the cause of the long time resulting from ship repairs using the Fishbone Diagram Method.The application of this fishbone diagram has four causal points, including people, methods, materials, and management.
Maintenance carried out using the reactive maintenance method has different levels of repair for each component.Improvements to ship body maintenance are also carried out by applying the preventive maintenance method, which is calculated by finding the values of the mean time between failure (MTBF) and mean time to repair (MTTR).The Mean Time to Repair (MTTR) calculation when making repairs using the formula, and the MTTR calculation can be seen below [8].Determining the Mean Time Between Failure (MTBF) calculation when carrying out repairs is done using a formula, and an example of a calculation using the MTBF formula can be seen below [4].The proportion of time the ship body equipment is used to obtain the correct and maximum work target for ship body repairs is totalled using calculations from the availability formula, such as the formula, and examples of calculations using the availability formula can be seen below [8].Work carried out on component damage is required to reduce the ship's breakdown time.1.The provisions obtained from the availability standard are obtained from the percentage of the IVARA standard that has a maintenance performance indicator value of 95% of the performance level of ship repair components that does not meet the target standards of world-class IVARA key performance indicators.The IVARA target is 95%.The total calculation of MTBF, MTTR, and availability obtained is attached in the form of Table 1 MTBF, MTTR, and availability values, which can be seen below [9].

Tabel 1. MTBF, MTTR dan Availibility
The calculations that have been carried out on data acquisition from seversion (S), occurrence (O), and detection (D) are obtained from the results of interviews, which are used to obtain the value of the risk  [7].

Period
Calculations made from the RPN formula are entered in the form of Table 2. Assessment of the Severity, Occurrence, and Detection Parameters for the Risk Priority Number (RPN) Calculation, which can be seen below.Selection of maintenance strategy criteria obtained from determining the RPN criteria The maintenance techniques used for predictive maintenance with an RPN criteria value > 300, preventive maintenance with a criteria value of 200 > > 300, and reactive maintenance with an RPN criteria value > 200 Can be seen in Table 3. Selection of Maintenance Criteria for RPN Values.Table 3 Selection of Maintenance Criteria for RPN Values.

Table 3. Selection of Maintenance Criteria for RPN Values
Repairs to ship body components will be carried out from 2020 to 2022, of which there are 7 components: ship body, ship floor, ship hat, ship bow, ship main hall, ship rear body, and ship handrails.Analysis is carried out on data processing obtained from repairs to each ship body component to calculate the risk priority number (RPN).The calculations carried out have obtained several RPN values for the ship's body components, where reactive maintenance is required for 5 components and preventive maintenance is required for 2 components.The application carried out using the FAST diagram is used to provide innovation in describing the concept of scheduling a digital ship body maintenance system.The test is carried out by looking for data when the sum of the values N' < N, which can state that the data obtained is sufficient, and vice versa if the data N' > N is insufficient data and additional data must be added [5].The results obtained from using the Minitab software obtained results that were smaller than the minimum number of samples required.The test is attached in table form, and to make it more accurate, we used the Goodness of Fit test from the Time to Repair (TTR) process in software form, Minitab.Tests carried out using Minitab software obtained results from the suitability of the distribution and the value of the smallest P-value from the Anderson-Darling value of the exponential distribution, with a value obtained of 1.581 from the normal, exponential, normal logarithmic, and Weibull tests carried out using the software.Minitab.Distribution testing and determination of distribution parameters will be carried out on the Time Between Failure (TBF) [10].Testing was implemented with a Goodness of Fit test from the Time Between Failure (TBF) process using Minitab software.Tests carried out using Minitab software obtained results from the suitability of the distribution and the smallest P-value of the Anderson-Darling value of the exponential distribution, with a value obtained of 1.919.

Conclusion
The conclusions that have been obtained from data processing and analysis, that the company's efforts to improve ship body maintenance performance and minimize breakdown time, need to be carried out using reactive maintenance methods and preventive maintenance methods to provide effective scheduling of ship body maintenance.The strategy using the Preventive Maintenance Method uses calculations from MTTR, MTBF, and availability, which give results of 78 days, 99 days, and 21.35%, which are used to find out the right time to carry out ship body repairs.The company's efforts to design predictive maintenance in ship body maintenance serve to facilitate inspection of each component.At this analysis stage, the use of the ship's body and bow components has a Risk Priority Number (RPN) value of 200 < RPN < 300, which means preventive maintenance is required.The rear body components of the ship, the ship's floor, the ship's main hall, the ship's handrails, and the ship's hat get a Risk Priority Number (RPN) value of RPN < 200, which means reactive maintenance is required.The company's efforts to measure performance use FAST diagram design by applying digital system concepts to simplify scheduling and checking stock of ship body equipment.All these maintenance system measurements really determine the right strategy for maintenance, so that the decisions taken can support the main final goal, namely sustainable industrialization.

Table 2 .
Assessment of Severity, Occurrence, and Detection Parameters for Risk Priority Number (RPN) Calculations