OSS Reliability Measurement and Assessment

In recent years, many computer system failures have been caused by software faults which were introduced during the software development process. This is an inevitable problem since a software system installed in the computer system is an intellectual product consisting of documents and source programs developed by human activities. Then, total quality Management (TQM) is considered to be one of the key technologies to produce more highly reliable software products. In case of TQM for software management, all phase of the development process, i.e. specification, design, coding, and testing, have to be controlled systematically to prevent software fault-introduction as much as possible and to detect the introduced faults in the software system as early as possible. Basically, the concept of TQM means to assure the quality of the intermediate products in each phase to the next phase. Particularly, quality control executed at the testing phase which is the last stage of the software development process is very important. During the testing phase, the product quality and the software performance during the operation phase are evaluated and assured. Concretely, a lot of software faults introduced in the software system through the first three phases of the development process by human activities are detected, corrected, and removed. Figure 1.1 shows a general software development process so-called a water-fall diagram.

In this chapter, we focus on the X desktop environment of which the product is the software system developed under the open source project.

In this chapter, in order to consider the effect of each software component on the reliability of an entire system in a distributed development environment, we apply the ANP (Analytic Network Process) which is a popular decision-making method. Moreover, we propose a method of reliability assessment based on the SRGM incorporating the interaction among software components. Also, we discuss a method of reliability assessment for OSS projects as a typical case of a distributed development environment.

Network technologies have made rapid progress with the dissemination of computer systems in all areas. These network technologies become increasingly more complex in a wide sphere. The mainstream of software development environment is the development paradigms such as concurrent distributed development environment and the so-called open source project by using network computing technologies. Especially, an OSS (open source software) system is used all over the world. Such OSS systems which serve as key components of critical infrastructures in our society are still ever-expanding now. The open source project contains special features so-called software composition by which several geographically-dispersed components are developed in all parts of the world.

Network technologies have made rapid progress with the dissemination of computer systems in all areas. These network technologies become increasingly more complex in a wide sphere. Then, software development environment has been changing into new development paradigms such as concurrent distributed development environment and the so-called open source project by using network computing technologies. The case of success includes OSS (Open Source Software) systems which serve as key components of critical infrastructures in our society. The open source project contains special features so-called software composition by which several geographically-dispersed components are developed in all parts of the world.

At present, there is growing interest in the next-generation software development paradigm by using network computing technologies such as a cloud computing. Considering the software development environment, one has been changing into new development paradigms such as concurrent distributed development environment and the so-called open source project by using network computing technologies.

At present, OSS (Open Source Software) systems serve as key components of critical infrastructures in the society. The open source project contains special features so-called software composition by which several geographically-dispersed components are developed in all parts of the world. The successful experience of adopting such open source projects includes Apache HTTP server, MySQL database server, OpenStack cloud software, Firefox Web browser, and GNU/Linux operating system, etc. However, the poor handling of quality problem and customer support has limited the progress of OSS, because the development cycle of OSS has no testing-phase.

Considering software development environment, there is growing interest in the next-generation software development paradigm by using network computing technologies such as an open source project and a cloud computing. The open source project contains special features so-called software composition by which several geographically-dispersed components are developed in all parts of the world.

Open source software (OSS) systems which serve as key components of critical infrastructures in the society are still ever-expanding now.

A cloud computing is now attracting attention as the next-generation software service paradigm because of the cost reduction, quick delivery, and work saving. In particular, third-party software development paradigm has been gaining a lot of attention in various mobile software development area, i.e., Android, OpenStack, and Apache HTTP server, etc. At present, OSS (Open Source Software) systems serve as key components of critical infrastructures in the society. The open source project contains special features so-called software composition by which several geographically-dispersed components are developed in all parts of the world. The successful experience of adopting such open source projects includes Apache HTTP server, MySQL database server, OpenStack cloud software, Firefox Web browser, and GNU/Linux operating system, etc. However, the poor handling of quality problem and customer support has limited the progress of OSS, because the development cycle of OSS has no testing phase.

We focus on the Xfce desktop environment “Olivier Fourdan, Xfce—Desktop Environment” [1] which is one of the software system developed under open source project. The Xfce is a lightweight desktop environment for UNIX-like operating systems. It aims to be fast and lightweight, while still being visually appealing and easy to use. The data used in this chapter are collected in the bug tracking system on the website of Xfce which consists of 6 components (called general, other, xfce4, xfdesktop, xffm, and xfwm) in November 2004 “Olivier Fourdan, Xfce—Desktop Environment” [1]. Tables 11.1, 11.2, 11.3, 11.4, 11.5 and 11.6 show actual data sets used in this section. “general” means the panel and utility, etc., “other” is the other components, “xfce4” is core components, “xfdesktop” is the background manager of desktop, “xffm” is the file manager, and “xfwm” is the window manager.

In this section, we analyze a set of actual software failure-occurrence time-interval data to show performance illustrations of software reliability/portability measurement for application of our tool.

This chapter shows several exercises for understanding the reliability assessment measures for OSS reliability measurement and assessment, e.g., MTBF, predicted relative error, and remaining faults. The following problems will be useful for software managers to evaluate OSS quality/reliability.