Scoring Method in ERP Bus Program with Multi-Criteria Decision Making (MCDM): AHP and WSM

Maintenance Support Division operated all of Bus Vehicle on Jobsite PT Mining Copper with the Bus manufacture IVECO. The IVECO Bus become critical vehicle to support mobilization employee and all residents on jobsite from Highland to Lowland vice versa. If there is a disruption, then the impact will be significant on company’ operational activities in general. Nowadays there are buses operations beyond its age or target life, and hourmeter that recommend by its manufacturer. It is estimate that the current method is not optimal due to require a long-time to determine an unconsidered cost. Therefore, it is requiring improvement on Equipment Replacement Plan (ERP) Bus Program based on the problem analysis. This research applies methods in Multi Criteria Decision Making (MCDM); Analytical Hierarchy Process (AHP), and Weighted Scoring Model (WSM), and problem analysis using Kepner-Tregoe Problem Analysis. It will be estimating the efficiency result with improved method compared to existing method. With the Decision Support System (DSS), this proposed method with MCDM is better than existing method, which can provide potential savings of $4.5 million per year on maintenance costs or $158 per hour on Cost per Hour at unit. 

Introduction

Replacement Bus Unit program on PT Mining Copper designed to replace buses that are already eligible for replacement taking things into account. In terms of determining the replacement of the current Bus unit, various things need to consider, namely the life age of unit, and the achievement of Hourmeter. The current business process in determining the replacement unit bus starts with the baseline requirement of amount Bus Vehicle is 172 Units determined by Company management, it means the minimum quantity of Bus available in jobsite to support transportation and mobilization within jobsite areas such as Lowland to Highland VV, within Lowland area and Highland arqea with total 172 Units for now. When determining on replacement unit timing and momentum, it is related to the equipment economic life and it is evaluated through four types of circumstances, equipment is unacceptable to work, equipment reached the target life or its life expectancy, equipment become out of date due to unavailability parts with advancement on technologies, and the last condition related to more efficient and more economical method proven (Raposoet al., 2019).

The manufacture reference related to age and hours limit to replace, the current determination based on technical data that collected from actual conditions in the field that taken from other departments such as Maintenance Department, existing decision model with decision tree due to decision-making model with decision tree method is simple and easy for the replacement program. The internal calculation said it is necessary to replace minimum 20 units of IVECO Trakker per year to regenerate existing units. After conducted interview with the stakeholders on the replacement Bus Program, with Kepner-Tregoe Problem Analysis (KTPA) decided that the causes of problem that occurs on many active bus units are exceed life target and still operated is combination of determine appropriate method on decision-making process and criteria to firm the replacement process of bus units, The possible cause also considers from knowledge and experience that later will verify to determine the verification process that support the main possible cause (Kepner & Tregoe, 1981).

The more data on maintenance, it can provide feedback to manufactures for improve the design in the future, therefore BSG is needed to collecting data from many sources, such as maintenance, planning, and operations. The more data gathered, it will create opportunities to more efficient on decision making process (Maet al., 2020). On ideal situation, method for prioritize equipment replacement with AHP method and solution developed related to model structure that includes quantitative and qualitative factors which can affect the replacement decision (Faisal & Sharawi, 2015).

As shown on Fig. 1 ERP Bus Simulation from year 2022 and beyond with amount of existing overdue unit buses more than half active unit, 91 units overdue/outstanding out of 172 active units.

Fig. 1. ERP bus simulation 2022 and beyond.

Literature Review

Decision Tree Analysis

Decision-making method that uses tree-like model with branch, symbols square to represent decision node, symbol circle to represent chance node, and symbol triangle is the endpoint of the branch or process, its representation on the graphic decision tree measure the probabilities to determine uncertain events, with value 0 represent impossible to 1 represent the probability of happen, this can explain qualitative and quantitative (Mittalet al., 2017).

Expected Monetary Value (EMV) required to determine by multiplying each outcome by its probability, then summing the products along the branch. Positive value of EMV is determine as profit, although positive EMV might reject if the probability of loss is too high. Therefore, the EMV can provide insight on the decision process. The EMV can calculated if Net Present Value (NPV) of object and probability of the outcome have been determined (Alkinaniet al., 2020).

Kepner-Tregoe Approach

This method provided systematic and step-by-step process. The Kepner-Tregoe (KT) approach steps consist of Situational Analysis (SA), Problem Analysis (PA), Decision Analysis (DA), and Potential Problem Analysis (PPA) (Hidayat & Hermawan, 2022). With this approach, it expected that constructed comprehensive problem-solving method by developed the structured framework, identify root causes, making decision, and potential problem looking into the future to identify and assess the threat and opportunity.

Decision Support System

Decision support system (DSS) is computer-based tools that helps users designate informed for decisions, generate reports to assist decision-makers in choosing the most suitable investments based on the goals and risk tolerance, the system developed to support the managerial decision making on situation semi-structured and structured (Husain, 2019).

Prior to develop the tools, there is process on data mining refers to Knowledge Discovery in Databases (KDD) with current internal database, the KDD declares related to overall process of discovering the useful learning refer to the data (Aroraet al., 2013).

Analytical Hierarchy Process (AHP)

The Analytical Hierarchy Process (AHP) is a decision-making method, it is a method structured strategy that used in distinct aspects, including business, engineering, project management, and more. AHP is a helpful tool when managed to multiple criteria and alternatives, it helps to prioritize and compare according to relative importance (Saaty, 1987).

The Consistency Ratio (CR) value is using the vector of priority, it is important that the consistency of respon from questionnaire of respondents maintain with value 0.10 or less (Song & Kang, 2016).

The priority weights derived from pairwise comparisons are aggregated through the hierarchical structure, the option with the greatest score is considered the most favorable choice (Khanet al., 2020).

Weighted Scoring Model (WSM)

Weighted Scoring Model (WSM) is the decision-making tool used to assess and rank alternatives or possibilities depending on multiple criteria. It used in any field to consider each option that can evaluated against factors or attributes. It simply said that these tools serve systematic process for selecting alternatives based on criteria. The alternatives chosen is the alternatives that have the highest score (Jadhav & Sonar, 2009).

This method main process to designate weight for each criterion and the most important criteria will have the highest percentage. The following step to implement the method of WSM (Ouchra & Belangour, 2021).

Framework 5W1H Method

The 5W1H method involves asking six key questions to gather comprehensive information, versatile approach that finds applications in journalism, problem-solving, project management, and various other fields. It helps in systematically analyzing and understanding a situation, problem, or event by exploring these aspects (Daman & Nusraningrum, 2020). Defining 5W1H as follows:

Who: Focus on individuals or groups involved.

What: Examine the core details or actions.

When: Pinpoint the timing or duration of the event.

Where: Identify the specific location.

Why: Explore the reasons or motivations behind actions.

How: Investigate the methods, processes, or mechanisms involved.

Research Method

Conceptual Framework

The conceptual framework builds with the four basics rational processes in Kepner-Tregoe Approach which consists of four main processes, as shown in Fig. 3, there are Situational Analysis, Problem Analysis, Decision Analysis, and Potential Problem Analysis (Kurniaet al., 2020).

The Potential Problem Analysis (PPA) is excluded on this paper due to unnecessary to define the PPA with change to Decision support system. with input current condition, process step include gap and improvement of current practice, and output is the expected condition. Further section the figure is explain the detail explanation of each process, from beginning to the end of process, as shown on Fig. 2.

Fig. 2. Conceptual framework.

Fig. 3. Research design.

Research Methodology

In this research, the design is using quantitative method with AHP, and Weighted Scoring Model (WSM) as explained in the conceptual framework. The tools that will be used to process data for both methods are Microsoft Excel by utilizing the formulas needed for calculations.

It is expected that both methods can answer the research questions, by providing provide a structured and objective way to evaluate and compare different equipment options, making the decision-making process more transparent, consistent, and based on an objective assessment by providing a clear framework for evaluation, and the scoring method will be a powerful tool that enhances the decision-making process and support better equipment replacement plan with its objectivity to avoid personal biases and opinions, consistency with measuring of Consistency Ratio and Consistency index, and the last is its efficiency in save times when dealing with a large number of equipment choices.

Data Collection Method

Primary Data and Secondary Data are required to explore the information about the topic. Primary data collected from distributing questionnaire to the expert or person that involved on the ERP Bus Program, while the secondary data required from company report, division report and department report (Fig. 4).

Fig. 4. Data collection methods.

The first research question primary data obtain from semi-structures interview with Business Support Group with questions list obtained from Kepner-Tregoe table (what, when, where, how much, possible cause, and verification) with supporting data of secondary sources from internal division data. The second and third research question primary data obtained from Focus Group Discussion (FGD) to determine criteria, alternatives, range of score and Questionnaire to determine global weight with processing data with pairwise comparison, determine global weighting, and calculate final score by weighting times score.

Data Analysis Method

Data collection from criteria and sub-criteria are established before, these data use to inform the actual evaluation of the bus equipment replacement alternatives. From data collection the AHP calculation starts with pairwise comparison data to obtain the weight of criteria, these calculations are based on mathematical calculations to determine an overall score for each alternative. The weight obtained in AHP is then calculated into Project Priority Matrix or Scored Priority Matrix to develop the priority of Buses unit, the final step is calculating the matrix to finalize the final scoring method for Buses units. The tools that will be used to process data for both methods are Microsoft Excel by utilizing the formulas needed for calculations (Fig. 5).

Fig. 5. Data analysis method.

Result and Discussion

Current Method and Proposed Method

Current Method

The current replacement of units refers to quantitative data Life Target and Hours Target, if required report condition every unit bus determined the condition and decide to keep or replace, the replaced unit collected to create the proposal, in the end BSG execute the proposal once approved.

The decision-making model with decision tree method is simple and easy to apply to the ERP Bus Program. Pre-discussion with Business Support Group inform that the shortcomings of current process that done manually by reviewing up to 172 units Buses one by one are time-consuming to determined up to hundreds of units and requires high accuracy to certain each element not abandoned, it is difficult to determine the priority for equipment replacement.

On the decision-tree method, every alternative given should have probability and at the end of process is calculated the Expected Monetary Value (EMV) where on the current method those two processes are missed, therefore the output currently produced has no score or qualitative (Fig. 6).

Fig. 6. Current decision-making process with decision tree.

Proposed Method

Multi-Criteria Decision Method (MCDM) with AHP framework that has been developed based on the current ERP Bus condition. With goals determine “select condition unit Bus Vehicle,” then breakdown into four criteria as follow, Life Target, Hourmeter, Maintenance Cost, and Cost per Hour. Alternatives are amount of all bus unit, from the data total 172-unit bus active for current situation, it is acquired from WSM method on scoring calculation and rank the priority unit bus for replacement (Fig. 7).

Fig. 7. MCDM framework with AHP & WSM.

Illustration of WSM used for the last step to rank the alternatives relative to their total score to determine the scale range of each criterion it can using Weighted Scale Model (WSM) or Prioritization Matrix method for develop, the score of scale range decided high score, medium, and the lowest.

Determine Criteria and Alternatives with FGD

The criteria and alternatives obtained from FGD with stakeholders, the following four criteria Life Target, Hourmeter, Maintenance Cost, and Cost per Hour, then alternatives are amount of all 172-bus unit. Data all buses unit related to these four criteria has been well recorded by stakeholders, in this case Business Support Group (BSG) Department.

Determine Range of Score for Criteria with FGD

Table I is the illustration and it is used for the last step to rank the alternatives relative to their total score to determine the scale range of each criterion it can using Weighted Scale Model (WSM) (Fig. 8).

Table I. Illustration of WSM

No	Bus unit	Life target	Hourmeter	Maintenance cost	Cost per hour	Total score
	Weight (obtain from AHP)	A%	B%	C%	D%	100 % (A+B+C+D)
1.	Bus 1	weight x scale	.	.	.	Weight x scale
2.	Bus 2	.	.	.	.	.
.	.	.	.	.	.	.
.	.	.	.	.	.	.
.	.	.	.	.	.	.
172.	Bus 172	.	.	.	.	Weight x scale

Fig. 8. FGD to determine criteria and alternative.

As per Table II, all criteria range have the typical score depend on its range with score 7 and 9 for high, 3 and 5 for medium, and 1 for low. Criteria Life Target divided into two types depend on Bus type Astra or Trakker, the high range if more than nine years (Astra), more than seven years (Trakker) with score 7 and 9, the medium range between 4 to 9 years (Astra) and between two to seven years (Trakker) with score 3 and 5, the low range below four years (Astra) and below two years (Trakker) with score 1. For criteria Hourmeter separated into two types depend on Bus type Astra or Trakker, the high range if more than 13500 hours (Astra), & more than 10800 hours (Trakker) with score 7 and 9, the medium range between 1500 to 13500 hours (Astra) & between 1200 to 10800 (Trakker) with score 3 and 5, the low range below 1500 hours (Astra) and below 1200 hours (Trakker) with score 1. Criteria Maintenance Cost if more than 60% new price categorized as high with score 7 and 9, between 30% to 60% categorized as medium with score 3 and 5, and below 30% categorized as low maintenance cost with score 1. The last criteria are Cost per hour, it calculated the delta that means changing year of year on cost per hour, if delta cost per hour more than 30% it categorized as high with score 7 and 9, delta between 5% to 30% is medium with score 3 and 5, and delta below 5% is low cost per hour with score 1.

Table II. Range Score for Criteria

Criteria	Weight	High score		Medium score		Low score
		9	7	5	3	1
Life target (Astra)	15.2%	>11	9 s.d 11	6 s.d 9	4 s.d 6	<4
Life target (Trakker)	15.2%	>10.5	7 s.d 10.5	4 s.d 7	2 s.d 4	<2
Hourmeter (Astra)	33.1%	>16000	13500 s.d 16000	7500 s.d 13500	1500 s.d 7500	<1500
Hourmeter (Trakker)	33.1%	>16000	10800 s.d 16000	5000 s.d 10800	1200 s.d 5000	<1200
Maintenance cost	39.5%	>120% New price	>60% New price	45%–60% New price	30%–45% New price	<30% New price
Cost per hour	12.2%	delta > 70%	Delta 30% s.d 70%	Delta 15%–30%	Delta 5%–15%	Delta < 5%

Analytical Hierarchy Process (AHP) Analysis

The first step of AHP to structuring the goals, criteria, and alternatives. The goal of this paper is selecting the unit bus that required to replace subject to criteria that determined by expert team with output the alternatives of selected top 20-unit bus per year that priority for replacement.

Online questionnaire distributed to respondents with finalization consist of five respondents that experts on their departments. The all respondent fills the questionnaire online, the data collected then processing on Business Process Management Singapore (BPMSG) website to do the pairwise comparison matrix, eigenvalue calculation, consistency check, deriving weight, and finally rank between criteria.

Calculation results of global weight the criteria that determined, with percentage obtain Life Target 15.2%, Hourmeter 33.1%, Maintenance Cost 39.5%, and Cost per Hour 12.2%, with total calculation all criteria at 100% (Fig. 9). Therefore, shortlisted rank from largest to smallest percentage are Maintenance Cost on the rank-1, Hourmeter on the rank-2, Life target on the rank-3, and Cost per hour on the rank-4. the global weight is aggregate value from all respondents that calculated by BPMSG website. The CR that consistent if value of it is below 10%, and all the questionnaire data reach value below 10% and all the questionnaires declare as consistent results as mentioned on the Table III.

Fig. 9. Global weight of criteria.

Table III. Respondent Table Result

Respondent	Life target	Hour meter	Mtc-cost	Cost per hour	CRmax
PW	4.2%	59.4%	23.9%	12.5%	4.0%
EJ	15.1%	54.4%	25.9%	4.6%	3.7%
GA	28.3%	59.1%	7.7%	4.9%	3.5%
AM	21.0%	4.6%	65.4%	8.9%	5.3%
AW	4.7%	9.8%	63.5%	22.0%	4.6%

Weighted Scoring Model (WSM) Calculation

Weighted that obtained from AHP method, then calculated by multiplying with range of score for the criteria the get the final score. The final score itself that required for the rank with top-20 score considered priority unit for replacement. All of unit on the top-20 have the high range on all criteria, life target, maintenance cost, cost per hour, and hourmeter with score up to 9. If a unit obtain score 9 or almost 9, it means that all criteria have exceeded the appropriate range, however maximum score on the priority list scoring method reach 8.7.

Decision Support System—Replacement Priority List

Decision support system have been developed with Microsoft Excel, simulation to all 172 Unit Bus to obtain the priority list on replacement bus. on the initial analysis from 172-unit buses no more than 50% with condition exceed standard or red flag categorized it is shown at Table IV.

Table IV. Condition Unit per Criteria

		High	%High	Medium	%Medium	Low	%Low	Total
Life Target	Astra	0	43.02%	38	36.05%	36	20.93%	74
	Trakker	74		24		0		98
Hourmeter	Astra	9	48.26%	65	51.74%	0	0%	74
	Trakker	74		24		0		98
MTC Cost		112	65.12%	35	20.35%	25	14.53%	172
Cost per hour		106	61.63%	49	28.49%	17	9.88%	172

Condition of all 172-unit bus depend on each criteria after Decision Support System calculation deliver results that Unit with category high life target achieve 43.02% as most of the bus population, meanwhile medium life target achieve 36.05%, and low life target reach 20.93%. For hourmeter criteria is about 51.74% categorized as medium hourmeter, higher than medium hourmeter that reach 48.26%, and low hourmeter 0%. Specific to criteria related to the cost, maintenance cost and cost per hour, it is obtained that more than 60% (Maintenance Cost 65.12% & Cost per Hour 61.63%) categorized as high cost, Medium Maintenance cost 20.35% and medium cost per hour 28.49%, and the rest is low categorized of maintenance cost and cost per hour that below 15% (14.53% for maintenance cost, and 9.88% for cost per hour). Due to this excessive cost will reduced as per priority list of Bus, it is an opportunity for Decision Support System tools to create and implement efficiencies cost wherever possible.

The top-20 of replacement priority list unit bus that must replace considering all criteria, for instance life target, maintenance cost, cost per hour, and hourmeter. Total score all unit have reach maximum of 8.7, and type of bus majority IVECO Trakker with composition Bus operation on Lowland is 13 unit, and Bus operation on Highland is seven unit.

Table V contain the top-20 of priority unit bus with grey highlight that must be replaced considering all criteria, for instance life target, maintenance cost, cost per hour, and hourmeter. Total score all unit have reach 8.21 and above, and type of bus majority IVECO Trakker with composition Bus operation on Lowland is 8-unit, Bus operation on Highland is 9 unit, and Bus SDO (Schedule Day-Off) 3 unit.

Table V. Weighted Scoring Model for Priority List Bus

EQUIP NO	EQUIP DECRIPTION	USER ASSIGNMENT	PURPOSE	Cost per hour average	Life target (Years)	Maintenance cost	Delta cost per hour	Hourmeter	Life target (15.20%)	MTC cost (39.50%)	Cost Per hour (12.20%)	Hourmeter (33.10%)	Total score
140312	IVECO TRAKKER	BUS OPERATION HL	REGULAR HL	37.1	9.7	133% of New Price	160%	17,492	7.00	9.00	9.00	9.00	8.70
140314	IVECO TRAKKER	BUS OPERATION LL	REGULAR LL	40.8	9.6	146% of New Price	109%	17,800	7.00	9.00	9.00	9.00	8.70
140315	IVECO TRAKKER	BUS OPERATION LL	REGULAR LL	37.7	9.6	124% of New Price	74%	16,276	7.00	9.00	9.00	9.00	8.70
140316	IVECO TRAKKER	BUS OPERATION HL	REGULAR HL	44.7	9.6	138% of New Price	1020%	18,038	7.00	9.00	9.00	9.00	8.70
140320	IVECO TRAKKER	BUS OPERATION HL	REGULAR HL	38.2	9.6	130% of New Price	155%	16,616	7.00	9.00	9.00	9.00	8.70
140332	IVECO TRAKKER	BUS OPERATION LL	REGULAR LL	33.8	9.5	127% of New Price	158%	16,672	7.00	9.00	9.00	9.00	8.70
140283	IVECO TRAKKER	BUS OPERATION LL	REGULAR LL	30.5	10.1	122% of New Price	44%	19,983	7.00	9.00	7.00	9.00	8.45
140287	IVECO TRAKKER	BUS OPERATION HL	REGULAR HL	39.3	10.1	127% of New Price	45%	16,083	7.00	9.00	7.00	9.00	8.45
140346	IVECO TRAKKER	BUS OPERATION HL	SDO	38.9	9.2	124% of New Price	40%	17,449	7.00	9.00	7.00	9.00	8.45
140351	IVECO TRAKKER	BUS OPERATION LL	REGULAR LL	37.0	9.2	148% of New Price	30%	18,903	7.00	9.00	7.00	9.00	8.45
140353	IVECO TRAKKER	BUS OPERATION HL	SDO	35.5	9.2	145% of New Price	63%	19,431	7.00	9.00	7.00	9.00	8.45
140358	IVECO TRAKKER	BUS OPERATION HL	REGULAR HL	33.7	9.1	129% of New Price	39%	18,369	7.00	9.00	7.00	9.00	8.45
140393	IVECO ASTRA	BUS OPERATION HL	SDO	30.5	7.9	137% of New Price	84%	16,470	5.00	9.00	9.00	9.00	8.39
140221	IVECO TRAKKER	BUS OPERATION LL	REGULAR LL	27.2	11.9	64% of New Price	78%	16,094	9.00	7.00	9.00	9.00	8.21
140281	IVECO TRAKKER	BUS OPERATION LL	REGULAR LL	38.4	10.1	120% of New Price	21%	17,012	7.00	9.00	5.00	9.00	8.21
140285	IVECO TRAKKER	BUS OPERATION LL	REGULAR LL	34.1	10.1	139% of New Price	29%	19,033	7.00	9.00	5.00	9.00	8.21
140304	IVECO TRAKKER	BUS OPERATION HL	REGULAR HL	35.1	9.7	120% of New Price	22%	16,601	7.00	9.00	5.00	9.00	8.21
140318	IVECO TRAKKER	BUS OPERATION HL	REGULAR HL	38.8	9.6	123% of New Price	27%	18,086	7.00	9.00	5.00	9.00	8.21
140331	IVECO TRAKKER	BUS OPERATION HL	REGULAR HL	33.8	9.5	141% of New Price	21%	19,110	7.00	9.00	5.00	9.00	8.21
140356	IVECO TRAKKER	BUS OPERATION HL	REGULAR HL	37.2	9.1	140% of New Price	21%	17,637	7.00	9.00	5.00	9.00	8.21
140223	IVECO TRAKKER	BUS OPERATION LL	REGULAR LL	26.6	11.9	81% of New Price	36%	18,908	9.00	7.00	7.00	9.00	7.97
140238	IVECO TRAKKER	BUS OPERATION LL	REGULAR LL	26.1	11.2	78% of New Price	58%	18,745	9.00	7.00	7.00	9.00	7.97
140246	IVECO TRAKKER	BUS OPERATION LL	REGULAR LL	38.7	11.0	111% of New Price	37%	17,683	9.00	7.00	7.00	9.00	7.97
140305	IVECO TRAKKER	BUS OPERATION LL	REGULAR LL	33.4	9.7	135% of New Price	8%	17,115	7.00	9.00	3.00	9.00	7.96
140299	IVECO TRAKKER	BUS OPERATION HL	REGULAR HL	19.3	9.9	70% of New Price	70%	18,564	7.00	7.00	9.00	9.00	7.91
140308	IVECO TRAKKER	BUS OPERATION HL	REGULAR HL	36.2	9.7	115% of New Price	103%	17,062	7.00	7.00	9.00	9.00	7.91
140327	IVECO TRAKKER	BUS OPERATION LL	REGULAR LL	25.0	9.5	99% of New Price	96%	18,473	7.00	7.00	9.00	9.00	7.91
140329	IVECO TRAKKER	BUS OPERATION LL	REGULAR LL	24.8	9.5	100% of New Price	75%	18,297	7.00	7.00	9.00	9.00	7.91
140390	IVECO ASTRA	BUS OPERATION HL	SDO	37.7	8.0	138% of New Price	90%	14,415	5.00	9.00	9.00	7.00	7.73
140253	IVECO TRAKKER	BUS OPERATION HL	REGULAR HL	26.7	10.8	76% of New Price	29%	16,585	9.00	7.00	5.00	9.00	7.72

Business Solution

The decision support system describes that 20-unit bus set into priority list for replacement in the next year with the new units. When the 20-units are replaced, there will be 152 units currently old unit in operation with 20-units is brand new, it can be simulated the rest 152 units average maintenance costs that will occur, which are estimated without considering the new 20-unit. This calculation steps are simultaneously applied to existing method for comparison.

Processing the existing and propose calculation of the rest 152 Unit that still on operations for criteria Cost per Hour and Maintenance Cost, those two criteria chosen due to related to costs.

Explained on the Table VI, the existing method with decision tree method, $ X obtained for cost per hour, meanwhile the proposed method with MCDM method obtained $ (X-158). Therefore, potential efficiency of Cost per Hour is $ 158 per hour.

Table VI. Potential Efficiency Cost

	Existing	Propose	Potential efficiency
Cost per hour	$ X	$ (X-158)	$ 158 per hour
Maintenance cost	$ Y	$ (Y-4.5 Million)	$ 4.5 Million per year

Whereas Maintenance Cost criteria with existing method achieved $Y per year, in the meantime the proposed method acquire $ (Y-4.5 million), Hence potential efficiency for maintenance cost per year of 152 Units is $4.5 Million.

The proposed method will also take less time to apply and consider the costs, this could be the response to the requirement for expected and firm method that is more straightforward and more comprehensive on utilize the data, hence it is expected to improve the existing conditions, and implemented once a year to support replacement bus program.

Implementation Plan

Suggestion for implementation plan are explained on this section, it is necessary to identified with 5W+1H framework (What, Why, Where, When, Who, and How) based on previous data process and analyze shows on Table VII.

Table VII. Implementation Plan with 5W1H

No.	Plan	What	Why	Where	When	Who	How
1.	Communicate the results of this thesis to related Stakeholders.	BSG should know the result of thesis	There are firm solutions to problem on ERP Bus	BSG Department, Maintenance Support Division.	Early Q3 or July, Before ERP Program started at that year	Researcher and BSG	Communicate the thesis result in the form of discussion between researcher and BSG
2.	Design to implement the proposed method refer to thesis result.	Create a plan before implementing the proposed method	Good on design will produce good on results	BSG Department, Maintenance Support Division.	End Q3 or September, As soon as stakeholders allow to apply the proposed method	Researcher and BSG	Plan for all possibilities by involving stakeholders during discussion
3.	Implemented the proposed method to ERP Bus Program.	Implementation is carried out in the ERP Program	Implementation of more firm method	BSG Department, Maintenance Support Division.	Early Q4 or October, A year before ordering unit on ERP Program	Researcher and BSG	Implementation and monitoring the process from beginning to ending of ERP Program

Conclusion and Recommendation

Conclusion

MCDM is consider applying, due to the simulation of this method deliver potential efficiency to the company. By using the MCDM method, more criteria will be considered, and it is more comprehensive when process the data. With MCDM also involving more parties or department, therefore the output of the process will be more objective compared to previous method. This method is the best alternative to avoid inefficiency of current method in replacing the buses, applying the MCDM method instead of existing condition, the MCDM deliver the best alternatives due to its process required less time, and comprehensive to consider criteria including the costs.

Comparing propose method to MCDM method will deliver potential efficiency of Cost per Hour is $158 per hour. Whereas Maintenance Cost criteria with existing method comparing to the proposed method will deliver potential efficiency for maintenance cost per year is $4.5 Million.

Considering the advantages that mentioned previously, it possible to the proposed method could be applied to units other than buses, for example other heavy equipment, truck, dozer, mobile crane, tractor, and small equipment. Therefore, the improved method can be applied more widely, not just on the one type of unit bus.

Recommendation

On this section the recommendation in terms of the business issue on ERP Bus program is improved the existing method of determining the condition Bus for replacement by developing more firm method using MCDM is consider applying, due to the simulation of this method deliver potential efficiency to the company. By using the MCDM method, more criteria will be considered, and it is more comprehensive when process the data. With MCDM also involving more parties or department, therefore the output of the process will be more objective compared to previous method.

It is possible that this method could be applied to units other than buses, for example other heavy equipment, truck, dozer, mobile crane, tractor, and equipment under Maintenance Support Division. This method can be done for other equipment by adjusting the relevant criteria for certain equipment and following the next process as in the method applied to ERP Bus.

Conflict of Interest

Authors affirm that there is no conflict of interest.