Service-ORIENTED ARCHITECTURE (SOA) IN LARGE OGRANIZATIONS

Service-Oriented Architecture (SOA) Alignment & Development

Measured in Large Organizations



Service-Oriented Architecture (SOA) Alignment & Development

Measured in Large Organizations

Introduction

Brief History of Software Architecture

Each time the story of the software architecture or software engineering, it is recognized that in the beginning, by 1968, Edsger Dijkstra, proposed the establishment of a proper structuring of software systems before embarking on schedule, writing code in any way (Dijkstra January 1983). Dijkstra, who argued that computer science was a branch of applied mathematics and suggested further formal steps to break down big problems, was one of those who introduced the notion of operating systems organized in layers that communicate only with adjacent layers overlapping onion-like layers. He invented or helped dozens of concepts is also necessary: ??the shortest path algorithm, the stacks, tables, lights, deadly embraces. In his essays started the tradition of referring to levels of abstraction has been so common in subsequent architecture.

Although Dijkstra does not use the term architecture to describe the conceptual design of the software, its concepts lay the groundwork for what would later express Niklaus Wirth (Wirth April 1971) and stepwise refinement and DeRemer and Kron (Kron 1976) as programming-in-the large or great programming ideas that would slowly decanting between engineers and architects first then.

An important development in the 1970s was the advent of structured design and the first explicit models of software development. These models began to rely on a more organic, evolutionary, cyclical, leaving behind the cascade development metaphors that were inspired rather on the assembly line of hardware engineering and manufacturing. Gradually the design was more independent of implementation, and forged tools, techniques and specific modeling languages.

At the same time, another important precursor, David Parnas, showed that the criteria selected in the decomposition of an impact the program structure and proposed several design principles to be followed to obtain a suitable structure. Parnas developed areas such as information hiding modules, structures and families of software programs (Parnas December 1972), always emphasizing the pursuit of software quality.

In 1972, Parnas published an essay in which he discussed how modularity in system design can improve the flexibility and conceptual control system, shortening development time. Then introduced the concept of information hiding (hiding information), one of the fundamental design principles in software design even today. In the second decompositions proposed by Parnas start hiding information used as a criterion. Each module then becomes a black box to the other modules of the system, which can access it through well defined interfaces, largely unchanged. In 1975, Brooks, designer of the OS/360 operating system and Turing Award 2000, used the concept of system architecture to mean complete and detailed specification of the user interface and believed that the architect is a user agent (Jr . 1975). Also distinguished between architecture and implementation, while saying that do, the implementation is concerned with how.

As Clements and Northrop written at this time (Northrop February 1996) in all subsequent development of the discipline remain ...