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ll street journal related a major software pany’s travails with a front page article entitled “Creating New Software Was an Agonizing Task …” these headlines, and many others like them, were a harbinger of a new understanding of the importance of puter software the opportunities that it offers and the dangers that it poses. Software has now surpassed hardware as the key to the success of many puterbased systems. Whether a puter is used to run a business, control a product, or enable a system , software is the factor that differentiates . The pleteness and timeliness of information provided by software (and related databases) differentiate one pany from its petitors. The design and “human friendliness” of a software product differentiate it from peting products with an otherwise similar function .The intelligence and function provided by embedded software often differentiate two similar industrial or consumer products. It is software that can make the difference. During the first three decades of the puting era, the primary challenge was to develop puter hardware that reduced the cost of processing and storing data .Throughout the decade of the 1980s,advances in microelectronics resulted in more puting power at increasingly lower cost. Today, the problem is different .The primary challenge during the 1990s is to improve the 2 quality ( and reduce the cost ) of puterbased solutions solutions that are implemented with software. The power of a 1980sera mainframe puter is available now on a desk top. The awesome processing and storage capabilities of modern hardware represent puting potential. Software is the mechanism that enables us to harness and tap this potential. The context in which software has been developed is closely coupled to almost five decades of puter system evolution. Better hardware performance, smaller size and lower cost have precipitated more sophisticated puterbased systems. We’re moved form vacuum tube processors to microelectronic devices that are capable of processing 200 million connections per second .In popular books on “the puter revolution,”O(jiān)sborne characterized a “new industrial revolution,” Toffer called the advent of microelectronics part of “the third wave of change” in human history , and Naisbitt predicted that the transformation from an industrial society to an “information society” will have a profound impact on our lives. Feigenbaum and McCorduck suggested that information and knowledge will be the focal point for power in the twentyfirst century, and Stoll argued that the “ electronic munity” created by works and software is the key to knowledge interchange throughout the world . As the 1990s began , Toffler described a “power shift” in which old power structures( governmental, educational, industrial, economic, and military) will disintegrate as puters and software lead to a “democratization of knowledge.” 20th century 60’s—70 age Traditional software engineering 1980s intermediate stages Object project At the end of 1980s Software process project 1990s Component project Figure 11 depicts the evolution of software within the context of. puterbased system application areas. During the early years of puter system development, hardware underwent