Endless Development is the Best Quality Assurance: The Case of “Hidemaru Mail”

: It is difficult to identify easily adaptable software in its completed form. In its nature, the definition of “complete” is unclear. As a result, if one expects perfection in software, software products will never be released; the only alternative is to release software if it runs, and then gradually refine it over time. This results in the implicit conventional wisdom that the “continuous development” of the software is the best quality assurance. This paper looks at the highly capable Windows e-mail software called “Hidemaru Mail.” With current progress in IT, it is possible that the concept of software quality assurance can be applied to a broader array of products and services.


Introduction
There is an implicit assumption that the development activity is a project and there is an "end" in theories to date. For example, Urban and Hauser's text on the product development (Urban & Hauser, 1980, pp. 61-76) states that projects begin with the creation of a concept and end with the release of a product into the market (Urban & Hauser, 1980, p. 66, Figure 4.1). In Clark and Fujimoto (1991), a typical study on product development, a framework for analysis of actual activities (Clark & Fujimoto, 1991, p. 23, Figure 2.3, p. 27, Figure 2.4) shows that development activities seem to end. 1 Within inter-project continuity studies (Aoshima, 1997;Aoshima & Nobeoka, 1997;Nobeoka, 1996), continuity is flagged as an issue because of the assumption that a particular development will end.
However, in contrast with the development activity of hardware, that of software appears to have no "end", for example, the birth of the IBM System/360 in the 1960s. Even though this system was released to its customers, the developers continued to fix software errors (or bugs) for several years after (Brooks, 1975(Brooks, /1995. In other words, the developers guaranteed the software's quality assurance by continuous (endless) development right from its inception.
Of course, this concept of quality assurance is as par for the course today. Microsoft fixes bugs via monthly updates to Microsoft Windows. Social Networking Services (SNS) and other web services modify features and specifications within days, hours, or even minutes. Online software 2 distributed over the Internet has similar 1 Kuwashima (2003) and Yasumoto (2006) are typical studies that analyze product development activities by turning projects into units. 2 Software developed for online distribution (via the Internet) is referred to "online software" herein. Online software is not only known as free software, freeware or shareware, but many internet games and open source software (OSS) currently available in Japan are online software. Raymond's (1997) pioneering research on online software primarily characteristics, and many other software applications and services have frequent upgrades.
Despite this fact, existing research on enterprise information systems, operating systems on PC (Cusumano, 1991;Cusumano & Selby, 1995;Cusumano & Smith, 1993), and software development activity in the Internet era (Cusumano & Yoffie, 1998;MacCormack & Iansiti, 1997) states that software development activity has an end. It begins with a requirements definition and ends with software moving into phases of system operation and system maintenance.
However, in reality this is not the case. has passed since the initial release.
Case Description: The Development of "Hidemaru Mail" 3 In this paper, we used a case study method based on interviews with Saito and supplemented secondary materials, such as Hidemaru Mail release notes and information from the Internet.

Road to establishing Saito Kikaku
Hideo Saito was a self-taught programmer in 1980 and began developing software. After attending the National College of

Contact with users and its advantages
Saito Kikaku provides support for software users via a "support forum." The support forum has "conference rooms" as subcategories These three "conference rooms" often delve into detailed discussions on features and specifications.

Discussion
The request from Xaxon was a catalyst for Saito Kikaku's venture. Saito kept up to these expectations and continued responding to bug reports and additional feature requests by these user groups. Figure 1 shows how Saito and users groups circulated information-bug reports and new feature requests-over the course of more than ten years. Saito's continual engagement without "end" established user groups' belief in "continual development in the future." This then became the best quality assurance of Hidemaru Mail.
In contrast, it goes without saying that NetMail, along with the AL-Mail, released around the same time, ceased this information circulation at some point. As a result, the software developers failed to establish this belief and quality assurance as Hidemaru Mail did. 19

Conclusion
Unlike tangible hardware products, software is easily adaptable. It is difficult to define the complete state of a software because it is unclear at what point the software may actually be finished. As a result, if perfection is expected, the software will never be released.
Software is released if it runs and then refined gradually over time.
This paper concluded that there is an assumption for software products: the "continuous development" of the software is the implicit conventional wisdom for the best quality assurance. Not only researchers but also practitioners are held captive by the belief that development activity has a defined end. This is probably because once a hardware product is completed and handed over to users, Endless development is the best quality assurance developers can no longer do any work on the product. Another reason is that it is taken as par for the course that if they are, corporations will provide quality assurance on their products, repairing them and solving defects as necessary.
However, in the case of software, these facts and par for the course do not apply. It is possible for developers to continue working on software even when that software is in the hands of users. As can be seen in the case of Hidemaru Mail, whether developers continue working on software depends on the developer's responses and desire. 20 Further, distinctions between software and hardware as well as corporate perspectives on quality assurance are changing. A hardware product's firmware can be changed even after the product is released into the market. Perspective on how much quality assurance a corporation should provide is no longer as certain as it once was.
For this reason in particular, we must reconsider the idea that development activities have an end. Researchers and practitioners alike cannot ignore the phenomenon of the IBM System/360 released in the 1960s. The development activities we see do not have an end because it is possible that the continuation of development activity lead to the best quality assurance.
However, continuing development activities is cost incurring. In addition, there is the risk of competing with one's own products (cannibalization). Thus, careful consideration must be given, even after a product is released, to whether the assurance of "continual development in the future" will be given to users. Companies may then put together product and development strategies based on these considerations.