History

Usage of the "alpha/beta" test terminology originated at IBM. Similar terminologies for IBM's software development were used by people involved with IBM from at least the 1950s (and probably earlier). "A" test was the verification of a new product before the public announcement. "B" test was the verification before releasing the product to be manufactured. "C" test was the final test before the general availability of the product. As software became a significant part of IBM's offerings, the alpha test terminology was used to denote the pre-announcement test and the beta test was used to show product readiness for general availability. Martin Belsky, a manager on some of IBM's earlier software projects claimed to have invented the terminology. IBM dropped the alpha/beta terminology during the 1960s, but by then it had received fairly wide notice. The usage of "beta test" to refer to testing done by customers was not done in IBM. Rather, IBM used the term "field test".

Stages of development

Pre-alpha

Pre-alpha refers to all activities performed during the software project before formal testing. These activities can include requirements analysis, software design, software development, and unit testing. In typical open source development, there are several types of pre-alpha versions. Milestone versions include specific sets of functions and are released as soon as the feature is complete.

Alpha

The alpha phase of the release life cycle is the first phase of software testing (alpha is the first letter of the Greek alphabet, used as the number 1). In this phase, developers generally test the software using white-box techniques. Additional validation is then performed using black-box or gray-box techniques, by another testing team. Moving to black-box testing inside the organization is known as alpha release.

Alpha software is not thoroughly tested by the developer before it is released to customers. Alpha software may contain serious errors, and any resulting instability could cause crashes or data loss. Alpha software may not contain all of the features that are planned for the final version. In general, external availability of alpha software is uncommon in proprietary software, while open source software often has publicly available alpha versions. The alpha phase usually ends with a feature freeze, indicating that no more features will be added to the software. At this time, the software is said to be feature complete. A beta test is carried out following acceptance testing at the supplier's site (alpha test) and immediately prior to general release of the software as a product.

Beta

Beta, named after the second letter of the Greek alphabet, is the software development phase following alpha. Software in the beta stage is also known as betaware. A beta phase generally begins when the software is feature complete but likely to contain a number of known or unknown bugs. Software in the beta phase will generally have many more bugs in it than completed software and speed or performance issues, and may still cause crashes or data loss. The focus of beta testing is reducing impacts to users, often incorporating usability testing. The process of delivering a beta version to the users is called beta release and is typically the first time that the software is available outside of the organization that developed it.

Software beta releases can be either public or private, depending on whether they are openly available or only available to a limited audience. Beta version software is often useful for demonstrations and previews within an organization and to prospective customers. Some developers refer to this stage as a preview, preview release, prototype, technical preview or technology preview (TP), or early access. Since the introduction of Windows 8, Microsoft has called pre-release software a preview rather than beta. All pre-release builds released through the Windows Insider Program launched in 2014 are termed "Insider Preview builds". "Beta" may also indicate something more like a release candidate, or as a form of time-limited demo, or marketing technique.

Beta testers are people who actively report issues of beta software. They are usually customers or representatives of prospective customers of the organization that develops the software. Beta testers tend to volunteer their services free of charge but often receive versions of the product they test, discounts on the release version, or other incentives.

Perpetual beta

Some software is kept in so-called perpetual beta, where new features are continually added to the software without establishing a final "stable" release. As the Internet has facilitated rapid and inexpensive distribution of software, companies have begun to take a looser approach to use of the word beta. In February 2005, ZDNet published an article about the phenomenon of a beta version often staying for years and being used as if it were in production level. It noted that Gmail and Google News, for example, had been in beta for a long time although widely used; Google News left beta in January 2006, followed by Google Apps (now named Google Workspace), including Gmail, in July 2009.

Open and closed beta

Developers may release either a closed beta, also called private beta, or an open beta, also called public beta; closed beta versions are released to a restricted group of individuals for a user test by invitation, while open beta testers are from a larger group, or anyone interested. Private beta could be suitable for the software that is capable of delivering value, but is not ready to be used by everyone either due to scaling issues, lack of documentation or still missing vital features. The testers report any bugs that they find, and sometimes suggest additional features they think should be available in the final version.

Examples of a major public beta:

Early customers purchased a "pioneer edition" of the WordVision word processor for the IBM PC for $49.95. In 1984, Stephen Manes wrote that "in a brilliant marketing coup, Bruce and James Program Publishers managed to get people to pay for the privilege of testing the product.”

In September 2000 a boxed version of Apple's Mac OS X Public Beta operating system was released. Microsoft's release of community technology previews (CTPs) for Windows Vista, between September 2005 and May 2006. From 2009 to 2011, Minecraft was in public beta which made it accessible to users across the world.

Open betas serve the dual purpose of demonstrating a product to potential consumers, and testing among a wide user base likely to bring to light obscure errors that a much smaller testing team might not find.

The Software Cycle – Part 1