Integration of DEMATEL and ANP Methods for Calculate The Weight of Characteristics Software Quality Based Model ISO 9126

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1 Integration of DEMATEL and ANP Methods for Calculate The Weight of Characteristics Software Quality Based Model ISO 9126 Sugiyanto Department of Informatics Institut Teknologi Adhi Tama Surabaya (ITATS) Surabaya, Indonesia Siti Rochimah Department of Informatics Institut Teknologi Sepuluh Nopember (ITS) Surabaya, Indonesia Abstract One of the difficulties that occur in the model is to decide the weights of quality characteristics. This is due to the interrelations existence among the quality factors based model ISO Each of these characteristics can influence or even contradict each other. The interrelations existence among the factors affects the weight of characteristics software quality, and will affect the software quality calculation. Therefore, researchers will integrate DEMATEL and ANP methods for calculate the weight of characteristics software quality based model ISO DEMATEL method used to calculate sum of influences for each characteristics model ISO 9126, while the ANP method used to calculate local weights and global weight for each sub characteristics model ISO Results from this study is the value of local weights for each of the characteristics of ISO 9126, and global weights for each sub characteristics ISO 9126 which represent the level of importance of the characteristics and sub characteristics ISO usually measured software quality using standard model ISO Reference [1] has used the AHP method to calculate software quality model ISO One of the difficulties that occur in the model is to decide the weights of quality characteristics. Reference [2] found how the interrelations existence among the quality factors based model ISO 9126 (fig. 1). Each of these characteristics can influence or even contradict each other, such as reliability between maintainability, or reliability between efficiency. Keywords software quality, ISO 9126, DEMATEL, ANP I. INTRODUCTION The number of software products from abroad benefit users because of the large choice of products and prices. It is a challenge for the domestic software products to enhance their international competitiveness. Developers and software houses in Indonesia need to pay attention to software quality issues in order not to fall behind from abroad. Measuring the quality of software is not an easy job. When someone gives very good value for a software, others not necessarily say the same thing. One's viewpoint can be oriented to one side of the problem, such as about the reliability and efficiency of the software, while others gives bad value for a software because it uses another viewpoint like aspect of the design and usability. Developers can view software quality from the perspective of the software development process (process point of view) and the perspective of the resulting product (product point of view). This assessment is affects the orientation to how the software developed as expected by the user. From the product point of view, practitioners and software developers usually measured software quality using model ISO From the process point of view, practitioners and software developers Fig.1. Interrelationship among the quality factors based model ISO 9126 [2] The interrelations existence among the factors affects the weight of characteristics software quality, and will affect the software quality calculation. Therefore, researchers will integrate DEMATEL and ANP methods for calculate the weight of characteristics software quality based model ISO Researches chose this method and refer [3] and [4], which have successfully integrated the methods for determining the weights of criteria and sub-criteria in many cases. II. LITERATURE REVIEW A. ISO 9126 Standard ISO 9126 was first introduced in 1991 through the definition of software quality [1]. The original 13-page document is designed as a foundation for further, more detailed, and have a standard that can processed. ISO 9126 introducing quality type quality where the following elements are known: 1. Effectiveness is the ability to make the user goal through accuracy and completeness. 2. Productivity is an effort to avoid excess use of resources, such as staff costs in the user goal.

2 3. Safety is trying to avoid the risk level for the crime and other entities such as business, software, property and the environment 4. Satisfaction is user satisfaction in using the software. ISO 9126 identifies six main characteristics of software quality are: 1. Functionality: the ability to cover the function of the software product that provides the user needs. 2. Reliability: the ability to care software with performance level. 3. Usability: skills related to the use of the software. 4. Efficiency: the ability to relate to the physical resources that are used when the software running. 5. Maintainability: the skills needed to make changes to software 6. Portability: the ability to relate the software that is sent to a different environment. B. DEMATEL (Decision Making Trial And Evaluation Laboratory) DEMATEL can be used to find and analyze the dominant characteristics of a system [5]. Through DEMATEL method, it can be seen that the dominant characteristic of the model of software quality, and most importantly will also note the relationship between characteristics that can later be used as input and decision-making models for ANP method. Input in this method is a questionnaire that respondents completed. Data results of the questionnaire is qualitative data converted into quantitative. So we get the impact relations map (IRM) at the result, which is the basis for modeling the ANP. In this process, there are several stages, start from : 1. Calculate the average first matrix using score. Sample of experts was asked to show a direct effect based on their perception that every element i influence every element other j, using a scale range from 0 to 4. High influence represented by 4, and no influence represented by Calculate the first influence matrix. 3. Creating relationship among the characteristic matrix in total. To create a matrix of values that have been normalized using formula (1), (2), (3): 4. Set the threshold value and generate impact relations map. This value is generated by taking into account the experts opinions are presented in the matrix element T. C. ANP ( Analytic Network Process ) ANP (Analytic Network Process) is an approach that allows the problem interdependence completion among the characteristics of alternative solutions [6]. The first stage of ANP is to compare the measurement criteria in the system to form a super matrix [7]. Here is the general form of the super matrix (8): The second stage of ANP is to generate weighted super matrix using formula (9): The third stage of ANP is raised limiting super matrix to calculate global weights using formula (10): III. RESEARCH FRAMEWORK (8) A. Flowchart System 0 d ij < 1 After getting a relationship matrix which has been normalized, then proceed with processing to obtain the total relationship matrix using formula (4), (5), (6), (7): T = D + D D m = D (I-D) -1 when m (4) Flowchart of this system show in fig. 2. Users enter the matrix influence the characteristics model ISO 9126 (for the DEMATEL method). Users also include the value of pair-wise comparison sub characteristics model ISO 9126 (for the ANP method). The system will calculate the first influence matrix, and create linkages between the characteristic matrix. Furthermore, the system will generate a weighted super matrix, and generate limiting super matrix. Finally, the system will display the output value of the local weights and global weights of each characteristics ISO The method used in this study include:

3 1. DEMATEL (Decision Making Trial And Evaluation Laboratory) used to calculate sum of influences for each characteristics model ISO ANP (Analytic Network Process) used to calculate local weights and global weight for each sub characteristics model ISO TABLE I CHARACTERISTICS AND SUB CHARACTERISTICS ISO 9126 Characteristic No Sub Characteristic Functionality Reliability Usability Efficiency Maintainability Portability 1 Suitability 2 Accurateness 3 Interoperability 4 Compliance 5 Security 6 Maturity 7 Fault tolerance 8 Recoverability 9 Understandability 10 Learn ability 11 Operability 12 Attractiveness 13 Time Behavior 14 Resource utilization 15 Analyzability 16 Changeability 17 Stability 18 Testability 19 Adaptability 20 Install ability 21 Conformance 22 Replace ability C. Implementation The first phase, users enter the matrix influences (fig. 3) based on their perception that every characteristic A effect on the other characteristic, using a scale ranging from 0 to 4. E.g. influences Reliability on Portability characteristics. Fig.2. Flowchart system B. Characteristics and sub characteristics model ISO 9126 Characteristics that considered in model ISO 9126 is 6 characteristics and 22 sub characteristics as shown in Table I. Fig. 3. Matrix influences form Furthermore, the user enters the value of pair wise comparison of each sub characteristics contained in model ISO 9126 (fig. 4). E.g. influences Accurateness on Security.

4 Fig. 4. Pair wise Comparison Sub characteristics ISO 9126 Click on a column filled with the value of pair wise comparison. Then, the questionnaire pair wise comparison form will appear (fig. 5). Users only need to enter the value of the interrelations of the ISO 9126 sub characteristic selected. E.g. influences Accurateness on Security. To help users, this form using the scroll bar that has a 2 way relationship that would represent the 2 sub characteristics model ISO 9126 interrelations existence. D. Output System Output from this application are as follows (fig. 6): Fig. 5. Pair wise Comparison Questionnaire The questionnaire using membership function (Table II) as used by [3] and [4] so that the user can enter data pair wise comparison qualitatively. Value TABLE II MEMBERSHIP FUNCTION Linguistic Variabel 1 Equally important / preferred 3 Moderately important / preferred 5 Strongly important / preferred 7 Very strongly important / preferred 9 Extremely important / preferred

5 Fig. 6. Output System Output of this application is the value of local weights for each characteristics ISO 9126, and global weights for each sub-characteristics ISO Fig.6 shows that sub characteristic Fault Tolerance is the most important sub characteristic and has the most impact in software quality assessment based model of ISO Sub characteristic Fault Tolerance has the highest weight is Operability is sub characteristic that has the least influence software quality assessment based on model ISO Sub characteristic Operability has the lowest weight is E. Discussions and Evaluation Researchers evaluated the system in the same way with the research [9] and [10]. Research [9] and [10] evaluated the system by comparing weights calculated using the proposed method and traditional methods. Traditional method using the

6 same input values with the proposed method, but ignore the interrelations existence among the quality factors. Comparisons of global weights of each characteristic between our proposed method and the traditional methods can be seen in Fig.7. methods can used to represent interrelationship among the quality factors based model ISO For the next study, subsequent research can combined fuzzy DEMATEL, and fuzzy ANP [8] methods to represent the important of characteristics and level of sub characteristic model ISO This study only discusses the weights of characteristics model ISO 9126, subsequent research can be done by adding the methods used to measure the quality of software e.g. integration method DEMATEL, ANP, and TOPSIS. REFERENCES Fig. 7. Comparisons of global weights of each characteristic between our proposed method and the traditional method Then, researchers show global difference weights of each characteristic between our proposed method and the traditional method in the graph (fig.8). Integration DEMATEL and ANP methods produce a more normal weight values, and proportionate. This is due to the interrelationship among the quality factors of ISO 9126 based models. Researchers have tested this application, and the results are appropriate with research [3] and [4]. IV. CONCLUSION Based on the results, it can concluded that the weight of characteristics software quality model ISO 9126 can calculated by using the integration DEMATEL and ANP methods. The result of this calculation is the value of local weights for each characteristics ISO 9126, and global weight for each sub characteristics ISO This integration [1] Behkamal, B.; Kahani, M.; Akbari, M.;, Customizing ISO 9126 quality model for evaluation of B2B applications. Elsevier Journal Information and Software Technology, [2] Zulzalil, H.; Ghani, A.; Selamat, M.; Mahmod, R.;, A Case Study to Identify QUALITY Attribute Relationships for Web Based Applications. Int. J. Comput. Sci. Network Security, vol. 8, pp , [3] Chaghooshi, A.; Fathi, M.; Faghih, A; Zarchi, M.;, Applying a New Integration of MCDM Techniques for Supplier Selection (Case Study: Pars Tire Company). Australian Journal of Basic and Applied Sciences, vol. 6(2), pp. 9-19, [4] Chen, J. K.; I, S. C.;, Using a novel conjunctive MCDM approach based on DEMATEL, fuzzy ANP, and TOPSIS as an innovation support system for Taiwanese higher education, Expert Systems with Applications, vol. 37, pp , [5] Tzeng, G.H., C.H. Chiang and C.W. Li;, Evaluating intertwined effects in elearning programs: A novel hybrid MCDM model based on factor analysis and DEMATEL, Expert Systems with Applications, 32: , [6] Ong, C.; Huang, J.; Tzeng, J;, Multidimensional data in multidimensional scaling using the analytic network process, Pattern Recognition Letters, vol. 26(6), pp , [7] Liou, J.; Tzeng, G.; H.C;, Airline safety measurement using a hybrid model, Journal of Air Transport Management, vol. 13, pp , [8] Yazgan, H. R.;, Selection of Dispatching Rules with Fuzzy ANP Approach, The International Journal of Advanced Manufacturing Technology, vol. 52, pp , [9] Yang, J. L.; Tzeng, G. H.;, An integrated MCDM technique combined with DEMATEL for a novel cluster-weighted with ANP method, Expert Systems with Applications, 38: , [10] Yang, Y. P. O.; Shieh, H. M.; Leu, J. D.; Tzreng, G. H.;, A Novel Hybrid MCDM Model Combined with DEMATEL and ANP with Applications, International Journal of Operations Research, vol. 5, no. 3, pp , Fig. 8. Difference global weights of each characteristic in graph