Daniel Trump
Lexis-Nexis Corporation
9595 Springboro Pike
Miamisburg, Ohio 45342
Tel: (513) 865-6800 ext. 5994
Fax: (513) 865-1786
Email:
daniel.trump@lexis-nexis.com
Reuse programs frequently need to evolve rather than launching as a full scale formalized reuse program. Supporting the evolution can be difficult because of the demands placed on the infrastructure by the initial state of the environment and the need to support a broad range of activities in a formal reuse program. Use of the inherent flexibility and power of the World Wide Web and web-based tools can assist reuse personnel in creating a supporting environment for development with reuse and for reuse.
Keywords: Reuse, World Wide Web, Internet, Reusable Assets, Catalogue
Workshop Goals: Networking with other reuse practitioners, gain exposure to practices, processes, methods, etc which may be applied to problems at Lexis-Nexis.
Working Groups: Reuse of Earliest Life-Cycle Artifacts, Component Certification Tools, Frameworks and Processes.
Lexis-Nexis has recently redirected its efforts in the area of software reuse from concentrating on simple common repositories of available software assets. Instead, a planned and coordinated approach that stresses software reuse as a integral part of the overall software development process is being taken. Several projects are under way to structure software application designs around frameworks or reusable components. Acceptance of commercial off-the-shelf software libraries as a replacement for home grown utility functions has spurred interest in reusable assets.
In addition to the focus on reusable software components, efforts are underway to provide a comprehensive development environment that integrates software reuse as part of the entire development process.
One of the most significant problems faced by reuse efforts in a commercial environment is that of being able to survive long enough to justify their existence to higher management. Developing a formal reuse program takes considerable time and investment. Corporate management, pressed by budget and schedule constraints, is frequently loathe to approve a project which doesn't show some immediate return.
While the best returns under a reuse program occur when reuse is planned rather than opportunistic, the latter type of reuse provides the quickest return. The raw material is already present for developers in the form of legacy code or commercial off-the-shelf software (COTS). By leveraging the available software a fledgling reuse program can get a start and evolve to more formalized reuse once it has "proven" itself to management.
Lexis-Nexis has been engaged in opportunistic reuse for years. It is currently seeking to transition to a more formal approach to reuse. However, the transition from opportunistic reuse to formal reuse cannot occur instantaneously. The transition must occur without abandoning valuable software available in the current repository that has become a defacto standard.
The requirement to maintain the current level of reuse while also developing and supporting formal reuse presents a significant challenge for the supporting infrastructure of tools. Among issues presented by the former requirement are the following.
The transition to formal reuse also offers challenges of its own for the supporting tools. The following are some of these challenges.
In addition to the requirements above, there are additional issues which, if addressed by the reuse infrastructure, would be of great assistance to the user community and the reuse group. These issue include the following items.
In order to address the above issues, a support infrastructure has been developed and is centered on the Internet and the World Wide Web (WWW). The complete package includes commercial off-the-shelf software libraries, in-house developed software libraries, configuration management tools, a locally developed documentation repository, and support tools for the development methodology of choice at Lexis-Nexis.The infrastructure is centered around a commercially available product, MOREplus.
MOREplus is a World Wide Web-based tool for cataloging a vast array of reusable assets. Using MOREplus developers can search for cataloged assets using natural language queries, search for patterns in the attributes of assets, and browse assets. Assets cataloged by MOREplus which are related can be internally linked through the tool.
By cataloging and classifying existing software assets, MOREplus resolves the issues of maintaining the current repositories. The source code files will be managed by a configuration management tool and referenced by MOREplus. Access to the source files will be through MOREplus links driving the configuration management tool.
Since the assets are only referenced by MOREplus and not actually maintained by MOREplus, the tool provides a centralized reference point for existing assets without adding to the maintenance burden of the reuse personnel. Maintenance of the actual source code is not increased by MOREplus' access to the files.
The more important feature of MOREplus is that it will also provide support for the developing formalized software reuse. Both natural language and keyword searches are available under MOREplus for assets cataloged with the tool. Relationships between assets are made explicit using the "related asset" attribute.
Use of the World Wide Web and Web based tools makes the issue of dealing with multiple platforms and different operating systems much simpler. Since MOREplus, through the WWW, can catalogue assets virtually anywhere on an internal net or on the Internet, assets can be distributed throughout the corporation, or at other sites on the Internet.
By combining web browsers with MOREplus, the reuse and development communities have access to assets from inside and outside the corporation. Access to internal information can be coordinated by cataloging the assets in MOREplus. External assets can be reached either through Web page links or by cataloging them as assets and linking to the URL.
In order to integrate the tool support for reuse with the rest of the development environment, MOREplus will be linked to the locally produced documentation repository. Documentation for the software libraries and for projects will be stored in the documentation repository and will be linked to the software through the MOREplus catalog tool.
Finally, Java applets will see increasing use to enhance the environment. Applets may be used to provide information about asset usage and tracking of assets. Use of Java to reformat assets according to user requirements is being examined. The ability of the Java language to enhance web-based sites and tools will become increasingly valuable as more of the development tools become web based and users become more reliant on the web as part of their development environment..
There is an ever increasing number of reusable component libraries available on the internet.The purpose for the existence of these libraries are as varied as the libraries themselves.Some supply software components or libraries, with and without a fee. Some act as a clearinghouse for software reuse information. Some are tailored to a specific environments or domains while others have no restrictions regarding the assets they provide. Some of the most notable web-based repositories are ASSET, ELSA, the ReuseIC, and CARDS.
ASSET is one of the most well known providers of reusable software assets. This site began as part of the STARS program and has evolved to being "primarily an on-line broker of digital products for the information technology and scientific communities" [1]. Many of ASSET's artifacts have a fee associated with their use. ASSET provides their services to virtually any user that desires access and is not tailored to any specific environment.
ELSA is another provider of reusable software artifacts from the World Wide Web. ELSA's origins are found in NASA's efforts to support ADAnet [2]. The ELSA WWW site uses the same technology as the reuse catalog portion of the infrastructure detailed earlier in this work. In fact, ELSA is the most visible success story for the MORE/MOREplus technology.
CARDS is a Department of Defense effort (hence the name for which CARDS is an acronym - Comprehensive Approach to Reusable Defense Software) to support systematic reuse [3]. It is targeted to a relatively specific audience and environment, but is visible to a much broader spectrum of software practitioners via their World Wide Web site. CARDS offers consulting services to organizations wishing to adapt their vision of reuse.
The ReuseIC, or Reuse Information Clearinghouse, is a site that serves as an index to Department of Defense reuse efforts. It consists pretty much of links to military software reuse programs. As such it doesn't really qualify as a repository itself, but it does give access to a considerable number of WWW sites where information and software can be obtained.
Each of the above named WWW sites are intended for public consumption. They are aimed, in some fashion, to reach a broad spectrum of software practitioners. While a given site, such as CARDS, may be intended to spread a particular view of software reuse, they do not include knowledge of the internal environment for which our tool infrastructure is being developed. The assets they make available are presented without any presumptions about how those assets will be used.
We know our environment so we can tailor currently existing tools, future tool acquisitions, current and future resources and plans, as well as structure the relationships between those entities, to better aid the introduction of formalized reuse. This tool infrastructure is built to support the specific environment in which it will operate. The infrastructure, as well as the assets that it offers to developers, is tied intrinsically to the environment,
Another corporation implementing a web-based reuse infrastructure is Texas Instruments. Texas Instruments, like ELSA, uses the MOREplus tool to support their reuse effort [4]. The paper described the structure adopted by TI as they set up their MOREplus tool and reuse repository.
Texas Instruments also reported linking the reuse catalog tool to other software support tools, specifically the configuration management tool. It is not known whether they have attempted to expand the links to include other reuse support tools.
Dan Trump is a Senior Reuse Software Engineer at Lexis-Nexis Corporation in Dayton, Ohio. His duties include researching reuse technology, consulting with development groups, and developing and implementing software reuse processes and procedures for the corporation. He also maintains and coordinates the current repository of software assets. Previously he has worked for Delco Electronics, Northrop Corporation, and General Motors. He received a MS in Computer Science from the University of Southern California in 1989 and a BA in Computer Science from Asbury College in 1983.