ارزیابی سیستم پشتیبانی CMMI بر اساس مدل معیار های کمی فازی

In Capability Maturity Model Integrated (CMMI), Lead Appraiser (LA) evaluates the processes of one company according to qualitative sources such as instrument, interview and document through direct artifacts, indirect artifacts and affirmation. Due to the subjective measurement and non-quantitative expression of LAs, this paper proposes a fuzzy quantitative integrated metric model (FQIMM) that combines Quantitative Software Metrics Set (QSMS), linguistic variables, interval of confidence and a new fuzzy number ranking method. It can help software companies to evaluate on quantitative approach and then know the status by their self more quickly and effectively. Moreover, a CMMI appraisal support system (CMMI-ASS) is developed to help self-assessment software companies to accomplish the appraisal process, which integrates a fuzzy number ranking method to rank the final result.

In recent years, software development companies and departments follow software process methodology (SPM) including ISO9000, Capability Maturity Model (CMM) and Capability Maturity Model Integrated (CMMI) for improving competitiveness and quality. Moreover, many researches investigate the impact of software process improvement on organizations performance and the situations (Ashrafi, 2003 and Li Eldon et al., 2002). Besides, the impact of software process improvement on organizations performance and the situations was investigated by many researches, such as Ashrafi, 2003, Li Eldon et al., 2002, Jiang et al., 2004 and Osmundson et al., 2003. In order to evaluate the maturity of the software development process in a software company, software measurements are needed and used to measure specific attributes of a software product or software process. This study area uses software measures to derive various objectives (Grady, 1987, Grady, 1990 and Grady and Caswell, 1987). In CMMI, the Lead Appraisers can know the effects and the performance of institutionalized process in one company according to Specific and Generic Goals, and Generic and Specific Practices defined in Process Area. Lead Appraisers can also evaluate in qualitative description based on questionnaire, interview and document by appraisal requirements for CMMI, and standard CMMI appraisal method for process improvement (SCAMPI) (Mellon Software Engineering Institute, 2001). The CMMI evaluation results are usually dependent on the Lead Appraiser’s subjective judgment. Therefore, Chen and Huang (2003) built Quantitative Software Metrics Set by appraisal requirements for CMMI and function point analysis (Garmus & Herron, 2001) and chose one category of each process area in CMMI Continuous for Quantitative Software Metrics Set. In Quantitative Software Metrics Set, ‘benchmark’ means the computing unit is calculated by function point, but cannot benchmark with certificated company. Also, according to (APQC, 1993), ‘benchmark’ was defined as “evaluating the practices of best-in-class organizations and adapting processes to incorporate the best of these practices (APQC, 1993)”. According to Kearns, the former CEO and Chairman of Xerox Corporation, says, “Benchmarking is the continuous process of measurement of products, services, and practices, related to the strongest competitors or the recognized companies that is leader in its field.” This paper accepts above definition and want to build a more feasible and flexible system for improving this process. However, in many decision-making situations, the values for the qualitative criteria are often imprecisely defined for the decision-makers (DMs) and the final scores of alternatives are represented in terms of fuzzy numbers. The evaluation of software maturity also must face this problem and we adopted the fuzzy numbers for describing Lead Appraiser’s judgment and knowledge. For above reasons, a ranking fuzzy numbers method based on two-dimensions dominance (Chang, Cheng, & Kuo, 2006) is adopted into the CMMI appraisal support system (CMMI-ASS) developed in this paper for handling the benchmark problems. In this paper, the preliminary will be introduced briefly in Section 2. FQIMM is proposed in Section 3. Then, the practical example and CMMI-ASS are introduced in Sections 4 and 6, respectively. The conclusion and future work will be presented in Section 6.

In this paper, a complete benchmarking model based on Cheng et al. (2009) for diagnosing software companies is proposed in this study. This model includes four process areas which are planning project (PP), process and product quality assurance (PPQA), requirements management and organizational process performance (OPP). By mean of the many examples and practical example, we show the method is more consistent with DMs’ thoughts, even is better than others. Moreover, the fuzzy quantitative integrated metric model (FQIMM) has the ability to measure the performance of CMMI in quantitative way and to rank the ordering for DMs. Finally, the real companies are illustrated by the proposed method. Due to the QSMS only focus on four of twenty-five process areas, this paper only measure and appraises on these four process areas. The advantages of the new proposed method are listed below: (1) QSMS is simplified to the understanding questionnaire and removed redundant question items. It can solve the qualitative/vague problems in appraisal. (2) A fuzzy number ranking method is adopted to rank the companies, and it is applied to the ranking order of CMMI level of software department. (3) In practical example, one company passed CMMI level 2 is invited in this research, and others can benchmark with it and improve the difference of each other. (4) Through the FQIMM, this paper assists organizations to accomplish self-assessment such as class B and C quickly and specifically. We hope that the extension for proposed model and developed system will be made in the future. For example, the higher level self-assessment for CMMI can be considered, or other management fields which need the experts’ subjective appraisal are also an interesting direction.