Machine Maintenance Scheduling Design Using Reability Centered Maintenance (RCM) method and Maintenance Value Stream Mapping (MVSM) at XYZ

The problem in this study is the occurrence of damage to the Oven, Mixer, Bread Sicer, Proofer, Despositor, Breadline, Vacuum sealer machines. XYZ has not yet scheduled planned maintenance on production machines . The purpose of this study is to determine the reliability of the machine in operating according to the desired function for a certain period of time at XYZ and to design machine maintenance scheduling at XYZ. This research is a quantitative research with the method used is Reability Centered Maintenance (RCM) and Maintenance Value Stream Mapping (MVSM). The data used is secondary secondary data obtained from XYZ, namely data on damage to Oven, Mixer, Brread Slicer, Proofer, Despositor, Breadline, Vacuum sealer machines in 2021. The results of this study state that the reliability of the machine operates according to its function states that Ovens had an average operating time of about 584 hours between 5 failures, breadslicer machines had an average time of about 1460 between 2 failures, proofer machines had an average time of about 1460 hours between 2 failures, breadline machines had an average time of about 1460 hours between 2 failures, vacuum sealers have an average time of about 2920 hours between 1 failure, and deposit machines have an average time of 2920 hours between 1 failure. Designing proper machine maintenance scheduling for XYZ, namely Mixer maintenance or replacement every 30 days, Depositors every 60 days, ovens every 90 days, proofers every 120 days, breadline siever 60 days, bread silicer every 60 days and vacuum sealer every 30 days.


INTRODUCTION
stated that just like humans, the condition of machines and equipment will experience a decrease in their ability to carry out their duties as they get older. In addition to the problem of engine age as an internal factor, there are several external factors that affect the ability of the machine to work. Some of these factors include errors in machine operation, errors in the installation of supporting equipment. The design of machine maintenance scheduling is a basic requirement in supporting user activities, especially in the operational activities of transportation machines, production machines, and other home equipment machines. Particularly in Indonesia, efforts to maintain these machine tools are very important considering the large comparison between the productivity of machine use and maintenance.
XYZ is an industry engaged in the manufacture of bread, which was founded by the late Alm. Willy Prayetno on April 2 2017, which is located at Jl. Palm Griya Indah Gurun Lawas, Padang, directly led by Yulzul Fazriat. This factory has approximately 30 employees. This XYZ produces several types of bread, namely white bread, sweet bread and dry sugar bread, in the production process for each product the machines are almost the same, namely, the first step is selecting raw materials, then the raw materials are weighed according to a predetermined dosage, then a mixing process will be carried out the dough (Mixing) and the frementation process, the next step is the forming stage e-ISSN: 2961-712X Vol. 2 No. 1, June 2023 DOI: 10.55299/ijec.v2i1.430 (Despositor) then the cutting stage (Bread slicer) and re-weighing will be carried out, the next process is roasting or baking (Oven), the finished bread is baked then brought to (Proofer) to carry out the developing stage and then cooled, some of the bread that must be filled, such as sweet bread, will be brought to (Breadline) to carry out jam filling, and ready for packing ( Vacuum sealer) or packaging. Roti New Prima Bakeri itself is spread throughout West Sumatra Province and parts of Jambi Province (Sungai Full and Kerinci) where currently XYZ has operational breakdown problems caused by unexpected damage to production machines. Information obtained from workers at XYZ, the scheduling of machine maintenance ( maintenance) carried out by XYZ is carried out based on damage (corrective maintenance), this causes continuous machine damage every month. Another problem is the unscheduled maintenance of production machines, this causes critical machines, namely, damage to the Oven, Proofer, Despositor, Breadline, Vacuum sealer, Mixer, Bread slincer machines. These problems will certainly cause operational termination (breakdown).
Research that has been carried out by (Marpaung, 2018) states that scheduling maintenance and maintenance of machines can be overcome by the Reliability Engineering and Maintenace Value Stream Mapping (MVSM) methods which have a positive impact, namely knowing machine reliability and being able to schedule machine maintenance effectively reducing breakdown risk production process. Therefore, planning production machine maintenance is very important.
Jayantari et al (2018) explained that Maintenance Value Stream Mapping is appropriate for scheduling machine maintenance on production machines. Then research has been carried out by (Manasyakana, 2018) in dealing with a problem of machine damage in the production process analyzed using the MVSM method and Lean manufacturing is applied to minimize downtime. (Indriati, 2019) states that one of the engine health factors that determines the smooth operation of the process is engineering reliability. According to (Damanik et al, 2020) provide alternatives and solutions to existing problems in mapping work station machine scheduling with MVSM and components on the machine. Ulfah & Ferdinand (2021). PT TMMI, Reliability engineering is appropriate for determining critical components, failure factors, MTBF and MTTR values, maintenance and appropriate maintenance schedules and proposing the need for critical spare parts to support the maintenance process, (Fathliana et al, 2020) application of lean manufacturing using maintenance MVSM value stream mapping to help create work station machine performance that can be relied on. (Rahmanto et al, 2021) the MVSM method is able to explore the possibility of shortening waiting times for repairs, waste, and highlighting important strategies. (Rimawan et al, 2021) explains that using the Reliability Engineering and MVSM methods can carry out engine maintenance / replace component parts when damaged components occur in production. (Sembiring et al, 2021) research using the Reliability engineering method to determine machine reliability and implement maintenance of factory machine components, concerning smoothness and congestion on production machines. Darno (2020) states that the decision that is applied in machine reliability chooses the Reliability engineering method. there are two materials that are used as thoughts, the system that will be analyzed, functions and malfunctions, components are an analysis process. Reliability engineering will provide clearer information in making system selection, and the system will be analyzed to determine engine reliability. (Sembiring et al, 2018) maintenance is organizing maintenance to provide a general view of the maintenance of production machine facilities, in an effort to maintain that each equipment and machine can be used continuously for production.
Then according to (Hidayat et al, 2021) MVSM succeeded in identifying problems that occurred as a result of waiting for service, reducing the waiting time for express maintenance services from 120.60 minutes to 64.00 minutes and succeeded in increasing service process capability. (Rusmawan, 2020) states that maintenance activities are to carry out periodic maintenance once a month, such as checking the oil, checking the carburetor and engine lubrication systems, repairing the engine or replacing engine components, MVSM is suitable to be implemented so that the company can carry out scheduled maintenance. (Bugvia et al, 2021) said that the MVSM method was able to explore the possibility of shortening waiting times, waste, and highlighting important strategies, steps that might be taken by management to increase machine productivity and quality in machine components.
(Nwanya et al, 2020) stated that the delay in the work station in producing was due to machine damage at the work station, the shorter the downtime, the faster the time to market products and reduce customer waiting time. Ansori & Mustajib (2013) Reliability Centered Maintenance where the implementation of this maintenance system is maintenance that is carried out before the occurrence of engine failure. This system is considered good enough to prevent unplanned machine stops and with this method is considered to be able to determine what actions will be taken to maintain physical assets. continue to operate as desired. (Sembiring & Nasution, 2018). Said Reliability engineering and MVSM are efficient tools as a determinant of engine reliability and engine maintenance planning.
This research was conducted to determine the level of reliability on critical machines and to design machine maintenance scheduling, using the Reability Centered Maintenance (RCM) and Maintenance Value Stream Mapping (MVSM) methods at XYZ. The advantages of the RCM method are to determine the reliability of more complex machines in operating according to the desired function for a certain period of time, and the MVSM method is to design scheduled machine maintenance. With this research it is hoped that it can be used as a support in research using the Reliability Engineering and Maintenance Value Stream Mapping (MVSM) method and also as a reference in further research. This study aims to determine the reliability of the machine in operating according to the desired function for a certain period of time at XYZ. To design machine maintenance scheduling at XYZ.

METHOD
This type of research is quantitative research with the category of systematic scientific research on parts and phenomena and their relationships. The research was conducted on the production floor of XYZ which is engaged in the production of white bread, sweet bread and dry sugar bread. XYZ is located on Jl. Plam Griya Indah Desert Lawas, Padang. Research will be conducted in December 2022. This research uses reliability centered maintenance (RCM) and maintenance value stream mapping (MVSM) methods. The data used is secondary data obtained from XYZ, namely data on damage to Oven, Mixer, Bread Slicer, Proofer, Despositor, Breadline, Vacuum sealer machines in 2021. Data processing begins with the reliability centered maintenance method which starts with making flowchars, Pareto diagrams, MTTF, FMEA, LTA and continues with the Maintenance Value Steam Mapping (MVSM) method.

Research result
Reliability Centered Maintenance (RCM) method, which is an application of design to machines, components or spare parts so that these components or spare parts can perform their functions properly, without any failure. , in accordance with the design or process when it is made, the proposed preventive maintenance uses the Maintenance Value Stream Mapping (MVSM) method. Reliability centered maintenance is a method that functions to ensure that several physical components of the machine at XYZ Bakery can function continuously by minimizing the occurrence of machine breakdown.

Flow chart
The flowchart is the steps or sequence in carrying out production machine maintenance, which can be seen as follows: 2) Pareto Charts Below is a pareto diagram of the total damage that occurred to XYZ which can be seen in  Bread slicer 2 1420 7 Vacuum sealers 1 2920 Source: Data processing Downtime data from machine components at XYZ can be seen in table 2 below: Bread slicer 2 1420 5% 7 Vacuum sealers 1 2920 5%

a. Identification of Priority Components Using Failure Modes Effect Analysis (FMEA)
In determining priority components using the FMEA method the first step is to find out the components of the machine in XYZ Bakery. Each component of the XYZ Bakery machine will be calculated with a Risk Priority Number (RPN). The first step in identifying priority components is knowing the initial data of the machine such as failure modes, causes, and failure effects, which are the failure modes for determines the detection category, causes determines the occurrence category and failure effect determines the severity category. Next is the calculation of the RPN value using the values from the severity, occurrence, detection categories.
After obtaining the data, the next step is to rank each component, while the ranking of each component using the FMEA table is as follows. FMEA is a method that aims to evaluate system design by considering the various failure modes of the system consisting of components and analyzing their effects on the reliability of the system. RPN is the mathematical product of the seriousness of the effect ( severity ), the likelihood that a cause will result in a failure related to the effect ( occurrence ), and the ability to detect failures before they occur ( detection ). The preparation of the RPN consists of components Severity of Occurance, Occurance, Detection Deficiency. The RPN value can be seen in table 3 below: with a safety of occurrence rate of 5, an occurrence rate of 25% and a detection deficiency level of 5, has an evident low risk so that the RPN value is 6.25.

b. Critically and Probability of Occurrence
This step aims to critically analyze what possibilities can occur in the system by using logic tree analysis and critically analysis for plant components.
1) Logic Tree Analysis (LTA) preparing a logic tree analysis is to give priority to each damage mode. Perform functional and fault review so that the failure mode states are not the same. The LTA process uses a simple logical question or decision structure into four categories, each question will be answered "Yes" or "No". The important things in criticality analysis are as follows: a) Evident, namely whether the operator knows under normal conditions, there has been a disturbance in the system? b) Safety, i.e. does this crash mode cause safety issues? c) Outage, i.e. does this damage mode result in all or part of the machine stopping? d) Category, namely the categorization obtained after answering the questions above. In this section the components are divided into 4 categories, namely: 1. Category A (Safety Problem), consequences for personnel and the environment.   Mixers Oven Vacuum

Data processing using Value Stream Steam Mapping (MVSM) Method
Following are the steps that can be carried out in the Value Stream Mapping method at XYZ, namely: 1) Identification of other processes and flows: identification of the bread production process and the flow of the bread-making process, including the oven 2) Time scale: Calculate the time required for each process and activity in the bread-making process, including the time required for the oven 3) Identification of wasted time: Identification of unproductive bread production time, including time lost due to damage to the oven . 4) Identification of Corrective Actions: Identification of actions that can be taken to reduce unproductive time and increase the efficiency of bread production, including servicing the Oven regularly 5) Implementation and Monitor: Implement corrective actions and monitor results these actions, including monitoring the performance of the oven and ensuring bread production continues to run efficiently and optimally. Because of this, the unitary function of the machine is recommended maintenance outside operating hours in order to reduce wasted time. a. Maintenance Scheduling Planning and Component Replacement After knowing the minimum downtime of the critical components of the cutting machine, a maintenance schedule can be made which will be able to assist the company in carrying out effective maintenance and minimize machine downtime and costs incurred. Below is a form of maintenance scheduling for each cutting machine component in January 2022 -December 2022.
Maintenance scheduling planning can be seen in After knowing the minimum downtime of the critical components of the cutting machine, a maintenance schedule can be made which will be able to assist the company in carrying out effective maintenance and minimize machine downtime and costs incurred. Below is a form of maintenance scheduling for each machine component at XYZ from January 2022 to December 2022.
The maintenance schedule can be seen in table 7 below:  Table 6 above can be seen the machine maintenance schedule according to the date, so that XYZ will find it easier to carry out maintenance or replace the machine if it has exceeded the useful life of the machine.

Reability Centered Maintenance ( RCM ) Data Processing Analysis
In the production process, because there is only one machine at each stage of the process, the selection is made of the machine that has the highest frequency of machine failures. Oven is the machine with the most frequency of failures. Data for each component in the form of system

1) FMEA analysis
After knowing the critical components of the machine at XYZ, an FMEA ( Failure Mode and Effect Analysis ) analysis is carried out and the RPN value of each component can be known. Mixers have an RPN value of 1, Depositors have an RPN of 0.15. proofen has an RPN of 0.8, oven has an RPN value of 6.25, breadline has an RPN value of 0.2. bread silcer has an RPN of 0.2 and vacuum sealer has an RPN of 0.05 ( table 3 ).
Based on the RPN values in table 3 , it shows the priority of a component that has the highest risk and requires corrective action. after filling in the FMEA worksheet table from one of the components of the XYZ machine is the oven. spare parts must be replaced. the failure effect caused by the oven is that the production of XYZ stops, because the oven has a function to bake dough with a safety of occurrence rate of 5, an occurrence rate of 25% and a detection deficiency level of 5, has an evidently low risk so that an RPN value of 6.25 is obtained.

2) LTA analysis
In LTA ( Logic Tree Analysis ) there is a malfunction caused by what, then what is the cause of the damage and what are the effects. Based on the results of the LTA analysis, several failure categories of each component can be identified. All components fall into category B (Outage Problem ). After the LTA analysis, the selection of actions is carried out which is the final stage of the RCM analysis process. From each damage mode, a list of possible actions is made and then the most effective action is selected. The selection of actions must be applicable and effective, currently maintenance actions on cutting machines are Run to Failure where the machine is operated until it is damaged so that machine maintenance tends to be corrective maintenance. After analysis with RCM, changes in action were obtained based on CD/TD actions.
The CD action aims to detect damage visually inspection¸ checking engine indicators, as well as monitoring a number of existing indicators. The components included in the selection of this action are the contactor and the driving machine. TD action is a maintenance activity and component replacement that is carried out regularly based on reliability calculations. The component included in the selection of this action is the Oven.
Based on the recapitulation of LTA damage, the highest damage was selected which was a priority, namely the Oven Machine on the machine at XYZ which has a function for baking dough. Criticality analysis (failure mode) is obtained as follows: 1. Evident (can the operator be aware of a failure during normal circumstances?) = No 2. Safety (can the failure endanger work safety?) = Yes 3. Outage (can this failure mode cause part or even the entire system to stop?) = Yes 4. Category: B (Outage problem), where a failure that occurs in a component makes the working system of that component stop. This affects operational plans, affects the quality and quantity of products, and creates additional costs. 2 failures, the vacuum sealer machine has an average time of about 2920 hours between 1 damage, and the depositor machine has an average time of 2920 hours between 1 damage (Can be seen in table)

MVSM Data Processing Analysis
Based on the results of data processing using the RCM method, the components included in the TD measure are calculated to determine the minimum downtime with the smallest TMD ( Total Minimize Downtime ) approach. A distribution test is carried out from the damage data for each component before determining the TMD value. The results of the TMD calculation obtained different results for each component. Mixer maintenance or replacement every 30 days, deposits every 60 days, oven every 90 days, proofer every 120 days, breadline every 60 days, bread silicer every 60 days and vacuum sealer every 30 days.

CONCLUSION
The conclusion from the researcher is the reliability of the machine operating according to its function states that the oven has an average operating time of around 584 hours between 5 faults, the breadslicer machine has an average time of around 1460 hours between 2 faults, the proofer machine has an average time of around 1460 hours between 2 failures, breadline machines have an average time of about 1460 hours between 2 failures, vacuum sealer machines have an average time of about 2920 hours between 1 failure, and depositor machines have an average time of 2920 hours between 1 failure. Designing proper machine maintenance scheduling for XYZ Bakery machines, namely Mixer maintenance or replacement every 30 days, Depositors every 60 days, ovens every 90 days, proofers every 120 days, breadline siever 60 days, bread silicer every 60 days and vacuum sealer every 30 days. Suggestions from this research are that it is hoped that the results of maintenance actions on critical components can be input for the company, so that XYZ can reduce downtime numbers and immediately take appropriate maintenance actions for oven machines. The company is expected to record complete data for machine maintenance on production machine components so that more complex problem solvers can be found. Future research can consider cost values, component reliability, more complex methods of maintenance action and longer time draws for more accurate efficiency results.