Selection of Quality Textile Materials as a Support for Supply Chain Management with the Weighted Product Method

Decision making is a matter that is very influential in the process of dealing with the selected alternative. At this time in making decisions is no longer just by human reason. Human limitations in thinking to solve a problem can now be assisted by computerization. The use of computers has developed from just processing data or presenting information, to being able to provide choices as a support for decision makers. The development of information technology has enabled decision makers to be made more quickly and accurately. The research aims to apply the weighted product method in reducing errors in the selection of quality textile materials. This research aims to facilitate the selection of quality textile materials. This research aims to be a good solution for khatialo shops in selecting quality textile materials. The weighted product (WP) method is one of the methods used to complete a decision-making system by considering the criteria and weights . Then proceed with the ranking process which will select the best alternative from a number of alternatives, in this case the alternative in question is the selection of quality textile materials based on the specified criteria. The results obtained with the highest rating value were achieved by the 4th alternative called Semi Sutra with the code TK04 alternative.


Introduction
Decision making is a matter that is very influential in the process of dealing with the selected alternative. At this time in making decisions is no longer just by human reason. Human limitations in thinking to solve a problem can now be assisted by computerization. The use of computers has developed from just processing data or presenting information, to being able to provide choices as a support for decision makers. The development of information technology has enabled decision makers to be made more quickly and accurately [1] Decision Support Systems (DSS) are part of a computer-based information system, including knowledge-based systems (knowledge management) that are used to support decision making within an organization or a company. Decision Support Systems are designed to support all stages of decision making starting from identifying problems, selecting relevant data, and determining the approach used in decision making, to evaluating alternative choices [2]. DSS is a system designed to be used as a tool to assist decision makers in making decisions, but this system does not replace one's capacity to make decisions, but is only used to provide consideration [3].
Supply Chain Management (SCM/Supply Chain Management) is an approach to produce and distribute in the right quantity, right location and right time in order to minimize costs and increase service satisfaction [4]. The SCM (Supply Chain Management) concept focuses on the main warehouse logistics section, namely product inventory sent to branch warehouses and small warehouses that are still experiencing product out-stock [5].
The weighted product (WP) method is often also known as the weighted sum method which belongs to the Multi Criteria Decision Making (MCDM) problem solving where to achieve the objectives of this method using optimal alternatives from a number of alternatives with certain criteria. Then proceed with the ranking process which will select the best alternative from a number of alternatives, in this case the alternative in question is the selection of quality textile materials based on the specified criteria [6].
The Weighted Product (WP) method is one of the methods used to complete a decision-making system by considering the criteria and weights [7]. The WP method is also called dimensionless analysis because its mathematical structure eliminates units of measurement. The WP method is a finite set of decision alternatives which are described in terms of several decision criteria [8].
Previous research on the comparison of decision support systems using the SAW and WP methods in lending found that the suitability level of the SAW method was 97.274% and the WP method was 99.80006%, thus the WP method is the most relevant method for solving lending problems [9].
Previous research on the decision support system for determining the location of a new shoe laundry business at BECKS using the WP (Weighted Product) method found that a decision support system designed according to needs for shoe laundry at BECKS was not an absolute decision, the assessment was also returned by the party. The calculation results obtained from determining the new location of the laundry business at BECKS which were ranked first were Jl. Madio Santoso No.102, Karakatau with a value of 0.0994 [10].

Research methodology
To assist in the preparation of this research so that the steps in solving the problems to be discussed can be clearly structured, it is necessary to have a framework arrangement. The research framework is in Figure 1: Research is a series of scientific activities in order to solve a problem. The function of research is to seek explanations and answers to problems and provide alternatives and answers to possibilities that can be used to solve problems. The stages in this research are as follows:

Preliminary Research
To carry out research, identification of problems is carried out by explaining an overview in the preparation according to the title by compiling a summary of the contents of each chapter per chapter which is divided into six sub-chapters, namely problem background, problem formulation, hypothesis, problem definition, research objectives and research benefits .

Data collection
The data usage technique used was to provide a data collection permission letter to the owner of the Khatialo Shop, Bukittinggi City and conduct interviews and observations.

Analysis
The analysis stage is intended to provide solutions to problems that have been determined based on the identification of the problems found.

Planning
Doing the design by manually calculating the decision support system for the Weighted product method and designing it in applying it to the program. At this stage also carried out the collection of facts that support the design of the system. By using UML (Unified Modeling Language) as a tool in explaining the flow of program analysis.

Implementation
This stage is carried out using the PHP and MySQL programming languages. Testing focuses on software in terms of logic and functionality and ensures that all parts are able to meet the requirements as written in the problem formulation in order to minimize errors (errors) and the resulting output is as desired.

Testing
The system built will be tested to find out whether the program is running well and in accordance with the design that has been done. The testing process consists of application testing and interface testing.

Data analysis
This study uses data on specifications and prices for laptops at the Khatialo Store, Bukittinggi City, which were updated in June 2022. The first thing that must be done in applying the Weighted Product method is to determine the criteria. There are five criteria that are used as a reference in decision making , which can be seen in Table 1 below: Based on the criteria and the suitability rating of each alternative that has been determined, then a value / weight will be given to each alternative on each predetermined criterion.

Price Criteria (C1)
The following is the conversion value of the price criteria, there are 5 conversion values, which can be seen in Table 2 below:  Table 3 below: 3. Material Criteria (C3) The following are the conversion values for the material criteria, there are 5 conversion values, which can be seen in Table 4 below

Motive Criteria (C4)
The following is the conversion value of the motive criteria, there are 2 value conversions, which can be seen in Table 5 below:

Color Criteria (C5)
The following are the conversion values for the color criteria, there are 3 conversion values for light, medium and dark, which can be seen in Table 6 below: The value of each sub-criterion is the result of inputting alternative textile product data which has been converted based on the predetermined criteria weights. The alternative codes for the products obtained can be seen in table 7. Data on the weight of specifications and prices for textiles based on the sub-criteria assessment can be seen in table 8.

Process Analysis
Weighted Product stages to determine the best product decision are as follows: 1. Determine the weight on each criterion 2. Determine the criteria category (benefit and cost) 3. Weight improvements 4. Determine the value of the vector S 5. Determine the value of the vector V

Weighted Products
The Weighted Product method is a method for completing Multi Attribute Decision Making (MADM). The technique used in Weighted Product performs multiplication to link attribute ratings, where each attribute's rating must be raised to the first power of the weighted attribute concerned. The calculation process using the Weighted Product method consists of several steps or stages. The first step is to determine the weight value of each criterion (W). In this calculation the value of W will be in the range from 0 to 1. Where the total value of W is 1. To get the normalized value of Wj by multiplying the attribute that is profitable (benefit) by 1, while the attribute is worth the cost (cost) multiplied by -1.
The process of the Weighted Product method is by multiplying each attribute against each alternative to link the attribute rating, where the rating on the attribute must be raised to the appropriate attribute

Alvi Martunasia
Journal of Computer Science and Information Technology Volume. 9 Issue 2 (2023) 107-111 4 weight. This is part of the so-called normalization process The following formula for alternative Ai is given as follows: = ∏ ; dengan i = 1,2 … . dst − Where ∑ = 1. is the rank that has a positive value for the attribute that has a profit value and a negative value for the cost attribute. The relative preference of each alternative is given as follows The criteria set require priority weights to find out how important these criteria are in order to get the appropriate decision results. The priority level can be seen in Table 9 below: The initial weighting and categories for each criterion in this research are actually determined, so the following is the determination of the criteria weights as an example of textile selection which can be seen in Table 10 below: In the weight improvement process, it is first determined which criteria are worth the benefits and costs. Previously, first correct the weight using the following formula: So after determining the w value for each criterion, then correct the weights as follows: Next is to do the calculations to determine the value of vector S as follows: After getting the vector value (S), the next step is to determine the vector value (V). After calculating the vector (V), the final value is produced for each alternative and the ranking from highest to lowest can be seen in Table 12 below: Based on the table above it can be explained that the highest rating value was achieved by the 4th alternative called Semi Sutra with the alternative code TK04, so it can be concluded that this textile is the best product at Khatialo Shop by calculating using the Weighted Product (WP) method.

System Testing
The following displays the program that has been built, including a login page which is the initial display when the website is accessed. Figure 2 below. The following page is the page for calculating the Weighted Product method by the admin .

Conclusion
Using the Weighted Product method in determining quality textile materials can minimize errors in selecting quality textile materials and the product supply chain system becomes computerized or an online sales system. The highest rating value was achieved by the 4th alternative called Semi Sutra with the Alternative code TK04, so it can be concluded that this textile is the best product at the Khatialo Shop by calculating using the Weighted Product (WP) method.