Independent Verification and Validation

for Internet Multimedia Systems

by Jeffrey S. Kline

Copyright: MediaNet Solutions, Inc. June 1998

Running head: IV&V FOR INTERNET MULTIMEDIA SYSTEMS

Abstract

Independent Verification and Validation (IV&V) can be applied to most types of system development efforts. One of the challenges for IV&V professionals is to update existing IV&V practices which can be applied to the ever increasing number of new, emerging, and diverse technologies. New and emerging technologies within the computer industry include multimedia, the Internet, and client-server. These technologies are converging and are resulting in a new breed of applications; Internet multimedia applications. With these new applications, it is becoming more and more critical to evaluate current IV&V practices with the focus of verifying that current practices are applicable to these new and emerging development efforts. The purpose of this paper is two fold. Firstly, the purpose is to identify unique variations in the system development life cycle attributable to the development of Internet multimedia applications. Secondly, the purpose is to recommend practices and techniques which can be applied to the system development life-cycle to assist in addressing these variations.

I. Introduction

Independent Verification and Validation (IV&V) can be applied to most types of system development efforts. These efforts range from military defense systems to single user database systems. One of the challenges for IV&V professionals is to continually update existing practices which can be applied to the ever increasing number of new, emerging, and diverse technologies. New and emerging technologies within the computer industry include multimedia, the Internet, and client-server. These technologies are converging in the development of powerful interactive multimedia-based applications. These applications run effectively across the Internet through the use of the Internet’s World Wide Web (WWW). As this trend gains momentum, it becomes more and more necessary for IV&V professionals to adapt and develop practices which can be applied to these new development efforts. Though standard IV&V practices can be applied to Internet multimedia system development efforts, certain variations exist. To compensate for these variations, innovated IV&V techniques and practices should be added to the IV&V process to make them more rigorous. Identifying these variations and adding rigor to the IV&V process will reduce system errors and compatibility problems.

Releasing systems with errors or compatibility problems can cost multimedia developers huge technical support dollars and valuable shelf space. Technical support costs already average $650,000 a year for multimedia developers, according to a recent MBR survey (MBR, July 1995, p. 5). The CD-ROM market is only one, but representative, component of the multimedia world. The worldwide number of multimedia CD ROM titles increased 80.2% to 9,691 in 1995 from 5,379 in 1994 (MBR, Jan. 1996, p. 15). A similar growth trend has been experience in the Internet arena.

In the past year, hundreds of newspapers and magazines have discovered that the Internet is the perfect place to publish specialized content for special interests. According to InformationWeek, Time Warner’s Pathfinder site on the World Wide Web is considered one of the best examples of a new business model. Pathfinder features on-line versions of Time Warner magazines such as Time, People, and Sports Illustrated. It also sells advertising and charges users for specialized services (InformationWeek, Sept. 1995, p. 148).

As multimedia, client-server, and Internet technologies converge and proliferate, it is becoming more and more critical to evaluate current IV&V practices with the focus of ensuring that current practices are applicable to these new and emerging development efforts. The purpose of this paper is two fold. Firstly, the purpose is to identify unique variations in the system development life cycle attributable to the development of Internet multimedia applications. Secondly, the purpose is to recommend practices and techniques which can be applied to the system development life-cycle to assist in addressing these variations.

II. Methods

Industry trade journal articles and selected text books were reviewed to establish current IV&V standards and practices being applied to multimedia Internet system development efforts. The results of these reviews were utilized to identify variations, and to develop practices and techniques which should be considered during Internet multimedia development efforts.

III. Results

Before proceeding with the discussion, it is important to define a few terms which will be used in the paper’s discussion. These terms are system development life cycle, IV&V, multimedia, client-server, the Internet and World Wide Web (WWW).

System Development Life Cycle

The system development life cycle (SDLC) for development efforts describes the span of time from a software systems conception through the useful life of a system. The SDLC is comprised of three major phases: the concept phase, development phase, and the operation phase. The concept phase typically involves the process of creation, filtering of ideas, feasibility studies, tradeoffs concerning costs and performance objectives, statements of operational concepts and capabilities, ultimate purpose and mission, and user considerations (Lewis, 1992, p.5). The development phase transforms the concept into a firm set of requirements, followed by a formal design. The design is then implemented. The components are then integrated, tested, and fixed until the system is ready for use. After the development phase is completed, the system is deployed and thus begins the operational phase (Lewis, 1992, p. 6).

The development phase of the SDLC is comprised of a requirements phase, design phase, implementation phase, and integration and testing phase. The requirements phase transcribes the necessary operational capabilities of a system into a clear definition of the system. Specifically, it identifies and defines a system’s subcomponents, and allocates functions, performance objectives, and physical constraints and attributes to each subsystem relative to the whole system (Lewis, 1992, p. 7). After the requirements phase, the design phase begins. The design phase is the translation of the functions the system is required to perform into the necessary logical, mathematical, and physical processes. The implementation phase covers fabrication of hardware, coding for software, and training. The integration and testing phase combines the parts of the systems and tests the systems against the defined requirements (Lewis, 1992, p. 7).

Independent Verification and Validation (IV&V)

IV&V is a series of technical and management activities performed by someone other than the developer of a system to improve the quality and reliability of that system and to assure that the delivered product satisfies the user’s operational needs (Lewis, 1992, p. 8). More specifically, verification is an iterative process aimed at determining whether the product of each step in the development cycle fulfills all the requirements levied on it by the previous step and is internally complete, consistent, and correct enough to support the next phase. Validation is the process of executing the software to exercise the hardware and comparing the test results to the required performance (Lewis, 1992, p. 9).

Multimedia

Multimedia is defined as a computer-based method of presenting information by using more than one medium of communication, such as text, graphics and sound, and emphasizing interactivity. In Microsoft Bookshelf, for example, you can see portraits of William Shakespeare, see a list of his works, and follow hyperlinks to related information. Advances in sound and video synchronization allow you to display moving video images within on-screen windows (Que’s Dictionary of Computer Terms, 1996).

Internet

The Internet is a system of linked computer networks, worldwide in scope, that facilitates data communication services such as remote login, file transfer, electronic mail, and newsgroups. The Internet is a way of connecting existing computer networks that greatly extends the reach of each participating system.

The Internet, in its first incarnation as the ARPAnet, was designed to serve military institutions, yet its technology allows virtually any system to link to it via an electronic gateway. In this way, thousands of corporate computer systems, as well as for-profit electronic mail systems such as MCI and CompuServe, have become part of the Internet. With more than 2 million host computers serving an estimated 20 million users, the Internet is exploding at the rate of a million new users each month (Que’s Dictionary of Computer Terms, 1996).

World Wide Web (WWW)

The WWW is a global hypertext system that uses the Internet as its transport mechanism. In a hypertext system, users navigate by clicking hyperlinks, which display another document (which also contains hyperlinks). What makes the Web such an exciting and useful medium is that the next document you see could be housed on a computer next door or halfway around the world. The Web provides a graphical user interface (GUI) for Internet applications. The WWW was created in 1989 at the European Laboratory for Particle Physics (CERN), a research institute in Switzerland. The WWW relies upon the HyperText Transport Protocol (HTTP), an Internet standard that specifies how an application can locate and acquire resources (such as a document, sound, or graphic) stored on another computer on the Internet. HTTP provides transparent, easy-to-use access to Web documents, FTP (File Transfer Protocol) file archives, Gopher menus, and even UseNet (Que’s Dictionary of Computer Terms, 1996).

Client-Server

Client-server technology is a design model for applications running on a network, in which the bulk of the back-end processing, such as performing a physical search of a database, takes place on a server. The front-end processing, which involves communicating with the user, is handled by smaller programs distributed to the client workstations (Que’s Dictionary of Computer Terms, 1996). More specifically, client-server architecture is a method of separating a database application into two parts. These parts run on different computers, communicating over a network or Internet. The client executes application software and interacts with the user, while accessing database information across the network. The server executes the database software and handles the functions which control the data required by the client. Client-server architecture makes it easy for one database to be shared by many remote clients (Magavi, 1995, p. 1224).

Convergence of Technologies To Create Internet Multimedia Applications

The WWW is the graphical multimedia interface to the Internet. The WWW requires users to utilize Web browsers in order to view WWW content information. WWW content information is generally text data, graphics, images, video clips and sound files. The Web browsers act as the client software systems while the Web content information is stored on a server which in essence is a database server. Thus, WWW applications utilize client-server architectures to present data in a multimedia format. WWW applications may also rely on third-party client-server database packages, such as Sybase’s SQL Server, as a database backend engine for processing/storing large data volumes.

WWW application programs are often developed using a multimedia scripting language such as HTML or JAVA. Such languages aim to hide low level implementation details (Subrahmanyam, P.A. 1995, p. 50). These languages provided mechanisms to present multimedia data and hooks to client-server database engines such as Sybase’s SQL Server or Oracle’s SQL Server.

IV. Conclusions

From the discussion above, it is obvious that Internet multimedia development efforts (IMDEs) involve many new technologies and thus offer many new challenges to IV&V professionals. Primarily, Internet multimedia applications (IMAs) differ from traditional applications in two distinct ways. Firstly, IMAs have constraints placed on them due to bandwidth (data transfer rate) considerations and need to be taken into account when developing these applications. IMAs which operate requiring too much bandwidth for the user-base become unusable because bandwidth problems result in the application performing slowly and these applications have a tendency to overwhelm the end-user’s computer resources causing lock-ups, system failures, and the like. Secondly, IMAs place a heavy emphasis on user-interface issues due to their reliance on multimedia data. Since IMAs data are comprised of text, images, graphics, animations, video and sound, the composition of the applications are presentation-based in nature. This shifts the emphasis in development to interface issues and away from more traditional development issues. More specifically, the following are variations, and practices and techniques which should be considered during Internet multimedia development efforts.

Variances, Practices and Techniques

Requirements Verification - Transcribing System Requirements

In IMDEs, requirements verification needs to ensure that the proper multimedia data characteristics are encapsulated. For instance, in defining graphic files which will be presented as part of the application, characteristics such as number of colors, graphic size, resolution, and file format need to be defined and verified as correct. For Video data, frame rate, data compression, size, and positing should be verified as correct. For Sound data, sound quality, bit sampling, and default volume should be verified as correct. Other types of multimedia data such as animations have similar but distinct characteristics which should also be defined and verified at this stage of the SDLC. To complete this type of verification, IV&V professionals need to develop a basic understanding of multimedia techniques and concepts.

Another aspect which needs to be verified is the relationship of the data to the client-server database backend (if part of the application). For instance, where data will be stored, how it will be stored, and methods for data retrieval should be verified as correct. This becomes a somewhat more important requirement in relation to the complexity of the data characteristics and the Internet data communications media the application travels across. To complete this type of verification, IV&V professionals need to develop a basic understanding of client-server techniques and concepts.

Additionally, telecommunication and networking aspects need to be verified as being transcribed accurately during this phase. IV&V specialists need to verify that these requirements have been properly stated and fit within the constraints of the intended environment. Implementation details such as transmission rates, bandwidth requirements, network topology capabilities, data transfer protocols, etc. need to be considered. For example, to verify a requirement to allow data to be transported at 10 megabytes per second, the wide-area network link, the local codex, the local cabling, and PC bus structures need to be verified as capable of meeting the data transport requirement. To complete this type of verification, IV&V professionals need to develop a basic understanding of telecommunication and networking techniques and concepts.

Design Verification - User Interface

During the design phase of Internet multimedia projects, IV&V professionals concentrate on the content of screens and not so much on the background software used to build them. It is important for the IV&V specialist to not only evaluate whether all content is presented in a logical manner, but that the content is presented in a manner which is consistent with the interface standard prevalent on the Internet and those standards being developed by Internet standards groups. Standardization of how information is presented is important on the Internet since thousands of organizations share this medium. Information which is presented in a non-standard way runs the risk of making the application difficult to use and/or unusable to the end-user.

Code Verification, Implementation and Testing - Static Analysis

During static analysis, construction fault detection becomes somewhat more complicated. In addition to evaluating the code standard adherence, variable set-use data, syntax errors, etc., the various multimedia data and their associated characteristics need to be evaluated and examined. Data such as graphic images need to be examined to ensure they contain the correct number of colors, file compression format, and size. Video data needs to be examined to ensure the proper frame rate has been implemented, data compression has been correctly implemented, and size and positing are correct. Sound data should be examined to ensure that the sound quality, bit sampling and default volume are correct. Examining these multimedia data characteristics will require IV&V professionals to add software and hardware tools to their IV&V toolset. An example of a new tool is a graphic viewing/manipulation programs useful in analyzing graphic compositions.

Summary

In summary, IV&V specialist need to increase their technical skills in the areas of multimedia, client-server and Internet technologies in order to be capable of properly applying IV&V techniques to the system development life-cycle. Additionally, IV&V professionals need to consider the current Graphical User Interface standards being utilized by the Internet and place an emphasis on verifying this component during the design phase. Finally, during the coding, implementation and testing phase, IV&V professionals need to verify that multimedia data was presented as required and this will require IV&V professionals added new software and hardware tools to their toolsets.

References

Lewis, Robert 0. (1992). Independent Verification and Validation. John Wiley & Sons, Inc.

Magavi, Sunil (1995). "Design and Implementation of Heterogeneous Distributed Multimedia Systems using Mosaic GSQL". Software - Practice and Experience. November 1995. p. 1223-1240.

MBR (1995). "STL Offers Title Publishers Bug and Compatibility Testing". Multimedia Business Report. July 14, 1995. p. 5.

MBR (1996). "Number of Multimedia CD ROM Titles Increase 80%". Multimedia Business Report. Jan. 26, 1996. p. 15.

Wilder, Clinton. "Managing Change". InformationWeek. Sept. 18,1995. p. 148-51.

Subrahmanyam, P.A. (1995). "Quality Assurance in Scripting". IEEE Proceedings. Summer 1995. p. 50-59.

Wong, Johnny (1996). "Synchronization in Specifications-based Multimedia Presentations". Software - Practice and Experience. January 1996. p. 71-80.

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