Testing Component-Based Software: A Cautionary Tale

and availability requirements entails enormous costs. Many organizations have begun to consider implementing such systems using reusable component repositories, with the expectation that ♦ commercial off-the-shelf (COTS) components or components designed for reuse can significantly lower development costs and shorten development cycles; and ♦ using them will ultimately lead to software systems that require less time to specify, design, test, and maintain, yet satisfy the high reliability requirements. Many organizations see the arrival of languages designed to implement software components as the silver bullet they have awaited for decades. They envision that writing a component once and reusing it in many subsequent software systems will effectively amortize the development cost among all users. They assume they can seamlessly integrate repository components into a new environment, and that COTS components are plug-and-play. In either case they see these components as building blocks that can be easily incorporated into a software system to provide specified functionality. Elaine J. Weyuker, AT&T Labs Testing ComponentBased Software: A Cautionary Tale We need new ways to va l idate so f t ware comp onents, sp ec i f i ca l ly those deployed in d iverse so f t ware env i ronments. We must a l so cons ider the l ike l ihood o f rea l i z ing ant ic ipated sav ings and whether comp onentbased sys tems can meet re l iab i l i t y and ava i lab i l i t y requi rements.