1. Introduction
Software must take on the role of managing the systems that support the infrastructures on which society depends. Given this degree of dependence, society has the right to demand the development of software products that are shipped with as few defects after shipment as possible. The venders that supply software products have difficulty in satisfying this requirement, however [1].
In response to the above, several different development and management techniques for improving the quality of software have been proposed. Among them, CMMI is widely applied worldwide. Unfortunately, even though a high level of CMMI is attained, satisfactory quality of software cannot always be obtained [2]. In fact, some development organizations with CMMI level 5 exhibit many defects after shipment.
The CMMI level 5 organization has spent three years working on improving software products that had exhibited many defects after shipment, based on the results of benchmarking other organizations with the same level, as part of its activities to reduce the number of defects after shipment. This paper describes the results. Based on the results, this paper discusses the software process conditions required to develop software products that have few defects after shipment. In this paper, a CMMI level 5 organization was selected as a case study because the loss of process areas itself has little effect on the number of defects after shipment, due to well-established software process of the organization.
2. Overview of Organization
This paper presents two CMMI level 5 organizations as a case study. These are called Organizations A and B. Organization A’s product exhibits a smaller number of defects after shipment than that produced by Organization B. Organization B planned improvement (Kaizen) measures by benchmarking A, and conducted Kaizen activeties. This paper outlines organizations A and B, and discusses the number of defects after shipment of the products produced by the organizations.
2.1. Organizations Characteristic
Organizations A and B belong to the same company and develop general-purpose IT-related software products in their different business areas. These organizations’ customer groups are basically in the same enterprise area. Organization A has almost the same shipment volume, development amount, and number of engineers as B. The two organizations applied almost the same software process and accomplished CMMI level of 5 in the early 2000s. Usually, they would apply V-shaped model and implement V&V. Their development techniques, such as those for design and testing, are almost the same. Both adopt the “Quality accounting” internally created and developed as a quality management method [3].
2.2. Number of Defects after Shipment
Figure 1 shows the number of defects after shipment in the products produced by Organization A and those of Organization B (see Organizations A and B before Kaizen). On the basis of the mean number of defects after shipment, assuming that the number of defects in the products of Organization A is 100, the number of defects in those of Organization B will reach 283. It can be shown that the number of defects after shipment by B is almost three times bigger than that appearing in the products of A. Organization B clearly had a problem with the number of defects after shipment in its products. This triggered Kaizen activities in Organization B.