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Normalized Systems is a theory to design and engineer information systems exhibiting proven evolvability. Originally established at the University of Antwerp, at the department (Management Information Systems ) of the faculty Applied Economics, it aims at re-creating information technology based on laws for software evolvability. ==Introduction== There exist severe problems in Information Technology today. Still many IT projects are reported as going over time, over budget, or not satisfying required specifications while contemporary organizations need to be more agile to keep up with the swiftly changing business environment. Some say that the same functionality seems to be built over and over again, in slightly different ways. Manny Lehman's law of Increasing Complexity captures this reality stating that: This law implies that the addition of new functionality to existing information systems becomes more complex- and therefore costly- over time. Indeed, software maintenance is considered to be the most expensive phase of the information system's life cycle, and often leads to an increase of architectural complexity and decrease of software quality. This actually resembles a widespread belief amongst practitioners, which is in line with the fact that information technology departments and budgets grow every year. Furthermore, Lehman argues also that as software becomes more complex, it eventually declines in usefulness. So as software grows in complexity and decreases in value as it does so, vendors have two options if they are going to be successful: increase maintenance fees so that they can deliver new software, or force an upgrade onto the customer.〔(Organized Robbery )〕 In Normalized Systems theory it's believed that today's IT problems are symptoms of something deeper and more fundamental. The theory is the result of identifying these fundamental principles, patterns and other methodological elements for building evolvable software architectures for enterprise systems. Indeed, the basic assumption of Normalized Systems is that information systems should be able to evolve over time, and should be designed to accommodate change. Normalized Systems principles define the rules according to which software architectures have to be built so that there are no combinatorial explosions in the impacts of predefined changes to the system. In Normalized Systems vision, Douglas McIlroy's dream of constructing information systems based upon rational principles becomes a reality. The main issue with regards to information systems is dealing with the ever increasing complexity at both the business and technical level. Even if the growing complexity is finally under control, there is always change. Indeed, our technology only comprises static modularity and no evolvable modularity. This transition towards evolvable modularity requires true engineering and determinism to combat change, i.e. applying principles to obtain a predictable and desired result. Eventually, the ultimate goal is mapping requirements to constructs in an invariable manner, incorporating a one-to-one traceability of data and functions, abandoning triviality as well as the reliance on top-quality heuristics, while truly embracing innovation through genuinely designing information systems that accommodate change. The result is high-quality IT using advanced modular structures of proven evolvability that realize McIlroy and withstand Lehman, introducing new levels of reuse and independent of software environment. In fact, Normalized Systems are a specific way of viewing service-oriented architectures (SOA), which are currently prevalent in academic literature. Indeed, the essence of SOA can be described as a new way of building high-level designs. Unfortunately, there are at this moment very few guidelines or laws on how this should be done, which is a major shortcoming. Normalized Systems principles can be seen as a contribution to solving this problem. Finally, the objective of the Normalized Systems research is to achieve straight-through processing. This term is used to refer to the tight coupling between a change at the organizational level, which is propagated straight to the architectural and implementation level. Normalized Systems theory integrates previous research by Herwig Mannaert on software architectures and their implementation with Jan Verelst's research on evolvability of conceptual models and design models of information systems. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Normalized Systems」の詳細全文を読む スポンサード リンク
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