Implementation of The Analytical Hierarchy Process (AHP) Method in The Laptop Election Decision Support System for Students and Community in Medan City

ABSTRACT


INTRODUCTION
The development of an increasingly fast and instant era in this millennial era, makes electronic devices, especially laptops, also experience very fast and extensive development. The capacity of a laptop is closely related to the price of a laptop, if the capacity of the laptop is higher, the price of the laptop will also be higher, and vice versa if the capacity of the laptop is lower, the price of the laptop will also be lower. However, each laptop offers different features of each type and gives each type a unique look and shape. This is what makes students and the public confused about which laptop to choose according to their wishes and the money budget they have so that they don't make the wrong choice in determining the type of laptop that students and the community want later.
Every student and society must have been in a position to determine a decision, to determine something between several choices or determine several things between certain choices. This is very difficult to decide if students and the community do not know what they want to decide whether it is in accordance with their needs and the financial budget they have. Each choice must have a path of determination or decision and a way to overcome it, whether it is solved directly or by using several alternative solutions to problems or solutions to problems that have been faced by students and the community.
Determining an election will be closely related to the decision support system. Therefore, this research was conducted to assist students and the community in choosing or determining which laptop suits their needs and financial budget. This research was conducted using the Analytical Hierarchy Process (AHP) method. This method is a form of a hierarchical decision support system that is determined by various alternatives and criteria so that later alternatives and criteria are obtained that are in accordance with the desired goals (saaty, 1993). In this case, the goal in question is to be able to choose or determine which laptop is in accordance with the financial needs and budgets of students and the community.

RESEARCH METHODE
According to Scott, a decision support system is a system that has a computer base and helps in making decisions from data and decision models in solving semi-structured and unstructured problems so that effective decisions are obtained.
Alavi and Napier stated that, a decision support system is a set of steps in the process of data and information that aims to use a model in order to get results from several answers that help make a decision.
Meanwhile, Al-Hamdany said that, a decision support system is a system that has information so that it can support steps in making a decision by explaining some information to solve problems and get some decisions.
From the several definitions of decision support systems that have been mentioned by the experts above, it can be concluded that a decision support system is an information system that has a goal in obtaining decisions that can facilitate management in solving a problem.

Understanding Analytical Hierarchy Process (AHP)
The Analytical Hierarchy Process (AHP) is a form of decision support introduced by Thomas L. Saaty. The form of decision support can solve a complex problem into a hierarchy. Saaty states, hierarchy is a view of a complex problem in a multi-level structure, where the first level is the goal, then there is the factor level, then the criteria, then the sub-criteria, and continues down to the final level of alternatives.
With a hierarchy, a complex problem with its group can be decomposed and then processed to form a hierarchy where all problems can be more structured and systematic.

AHP Stages
In the Analytical Hierarchy Process (AHP) there are the following steps (Kadarsyah Suryadi and Ali Ramdhani, 1998): a. Determine the problem and the expected solution. In this step, it is necessary to define the problem to be solved clearly and in detail. With the problem defined, find a solution that fits the problem at hand. The solution obtained can be more than one which will be further developed in the next step.
b. Defines a hierarchical structure starting with the main goal. After determining the main objectives at the top level, it is continued to develop the hierarchical level at the bottom, namely the appropriate criteria in assessing the given alternatives and determining these alternatives.
c. Create a pairwise comparison matrix that describes the relative contribution. In this step, the matrix used is a simple one, where the matrix has a strong level of position under consistent conditions, obtains other data that will be needed in all possible comparisons and can analyze prioritization awareness as a whole as a change in consideration. The matrix approach describes the dual aspects of prioritizing, namely mastering and being mastered. The comparison activity is carried out on the basis of criticism from decision makers where decision makers assess how important an element is over other elements. In starting the pairwise comparison process, a criterion is selected from the top level for example K, after that from the bottom level the elements to be compared are taken, for example E1, E2, E3, E4, E5.
d. Determining pairwise comparisons which will later get the total number of n x [(n-1)/2] pieces, where n is the number of elements being compared.
The result of comparing each element will be in the form of a number from 1 to 9 which shows the comparison of the importance of an element. If an element in the matrix performs a comparison with itself, the result is 1. The pairwise comparison scale can be seen below. 1 = Two elements are equally important. 3 = One element is slightly more important than the other. 5 = One element is more important than the other. 7 = One element is clearly more absolutely important than the other. 9 = One element is absolutely important over another. 2,4,6,8 = It is a value that exists between two adjacent values of consideration. e. Looking for eigenvalues and testing for consistency. If the eigenvalues are not consistent then repeat the process of retrieving data. f. Repeat steps 3,4, and 5 at all levels of the hierarchy. Looking for eigenvectors in all pairwise comparison matrices that form the value of all elements in determining the element at the lowest level of the hierarchy until the goal is achieved. Counting is done by adding up the values of all the columns in the matrix, dividing all the values in the column by the total column to get a normalized matrix, and summing the values in all rows and dividing by the number of elements so that an average is obtained.
g. Perform hierarchy consistency checks. What is calculated in the Analytical Hierarchy Process (AHP) is the consistency ratio by looking at the consistency index. The desired consistency is close to perfect so that close to valid decisions can be obtained. Although difficult to touch perfect, the expected consistency ratio is less than or equal to 10%.
The formula determines the consistency ratio (CR) of the consistency index of a matrix of order n:CI = − −1 Description : CI = consistency index (consistency index) λ maximum = the largest eigenvalue of a matrix of order n, maximum is obtained from the sum of the product of the column by the principal eigenvectors. Suppose C.1 = 0, meaning the matrix is consistent.
The inconsistency limit is calculated using the consistency ratio (CR), which is the comparison of the consistency index with the random generator value (RI). The value of RI depends on the order of the matrix n.

RESULT AND ANALYSIS
Analytical Hierarchy Process (AHP) is a decision-making method that produces rational decisions. Rational decisions are defined as in making a decision to achieve the desired goal, one must be able to determine the best decision. Rational decisions include alternatives and desired criteria based on existing sources. There are several stages of decision making: 1. Intelligent 2. Modeling 3. Choice

Intelligent Stage
The intelligent stage is a stage where we must collect and develop a selection criteria. In this case there are several stages that must be considered in the selection of laptop criteria, namely: In accordance with the existing data, the weighting of each criterion is adjusted to the value of its importance and is also adjusted to the provisions of the Analytical Hierarchy Process (AHP) method as follows: 1 Price Weight The price weight criteria consist of 5 Analytical Hierarchy Process (AHP) numbers as shown in the following table:        g. Excellence = 5 (Very good)

Modeling Stage
In the modeling stage, the approach model we chose was the Analytical Hierarchy Process (AHP). Entering this stage there are several things that must be considered, namely:Penggambaran Hierarchy keputusan In this section, we will discuss the grouping of the data results that have been described in the intelligent stage above, such as: a. The purpose that will be discussed regarding the selection of a laptop b.The criteria discuss price, screen size, processor type, memory capacity, memory type, hard disk capacity and advantages c.Alternatives to discuss laptop brand names 1 Determine the weight of the criteria based on voters' perceptions In this section, we will discuss determining the weight of the criteria based on a voter which has a scale value from 1 to 9 according to the interests of the voter. In making this comparison matrix, we have to adjust to inputting data from voters using the following steps: a. Creating a comparison matrix b. Create a criterion value matrix c. Using the consistency index (CI) formula d. Using the consistency ratio (CR) formula The table for the overall weight of the voter perception criteria is as follows:   And so on to find the global priority value on Laptop B, Laptop C, and Laptop D. so that you get the following results: Tabel 4-2 Nilai Prioritas Global So from the results of the calculations that have been carried out and are also supported by the determination of predetermined criteria, it is concluded that Laptop C is recommended as the best choice to buy because the highest value of global priority obtained by Laptop C is 0.17012.