Spiral Model free essay sample

The spiral model combines the idea of iterative development (prototyping) with the systematic, controlled aspects of the waterfall model. It allows for incremental releases of the product, or incremental refinement through each time around the spiral. The spiral model also explicitly includes risk management within software development. Identifying major risks, both technical and managerial, and determining how to lessen the risk helps keep the software development process under control.The spiral model is based on continuous refinement of key products for requirements definition and analysis, system and software design, and implementation (the code). At each iteration around the cycle, the products are extensions of an earlier product. This model uses many of the same phases as the waterfall model, in essentially the same order, separated by planning, risk assessment, and the building of prototypes and simulations. Documents are produced when they are required, and the content reflects the information necessary at that point in the process. We will write a custom essay sample on Spiral Model or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page All documents will not be created at the beginning of the process, nor all at the end (hopefully). Like the product they define, the documents are works in progress. The idea is to have a continuous stream of products produced and available for user review. The spiral lifecycle model allows for elements of the product to be added in when they become available or known. This assures that there is no conflict with previous requirements and design. This method is consistent with approaches that have multiple software builds and releases and allows for making an orderly transition to a maintenance activity.Another positive aspect is that the spiral model forces early user involvement in the system development effort. For projects with heavy user interfacing, such as user application programs or instrument interface applications, such involvement is helpful. Starting at the center, each turn around the spiral goes through several task regions. ?Determine the objectives, alternatives, and constraints on the new iteration. ?Evaluate alternatives and identify and resolve risk issues. ?Develop and verify the product for this iteration. ?Plan the next iteration.Note that the requirements activity takes place in multiple sections and in multiple iterations, just as planning and risk analysis occur in multiple places. Final design, implementation, integration, and test occur in iteration 4. The spiral can be repeated multiple times for multiple builds. Using this method of development, some functionality can be delivered to the user faster than the waterfall method. The spiral method also helps manage risk and uncertainty by allowing multiple decision points and by explicitly admitting that all of anything cannot be known before the subsequent activity starts.WATERFALLS CYCLE The waterfall model is a sequential design process, often used in software development processes, in which progress is seen as flowing steadily downwards (like a waterfall) through the phases of Conception, Initiation, Analysis, Design, Construction, Testing,Production/Implementation and Maintenance. The unmodified waterfall model. Progress flows from the top to the bottom, like a waterfall. The waterfall development model originates in the manufacturing andconstruction industries: highly structured physical environments in which after-the-fact changes are prohibitively costly, if not impossible.Since no formal software development methodologies existed at the time, this hardware-oriented model was simply adapted for software development. The first known presentation describing use of similar phases in software engineering was held by Herbert D. Benington at Symposium on advanced programming methods for digital computers on 29 June 1956. This presentation was about the development of software for SAGE. In 1983 the paper was republished with a foreword by Benington pointing out that the process was not in fact performed in strict top-down, but depended on a prototype.The first formal description of the waterfall model is often cited as a 1970 article by Winston W. Royce, though Royce did not use the term waterfall in this article. Royce presented this model as an example of a flawed, non-working model (Royce 1970). This, in fact, is how the term is generally used in writing about software development—to describe a critical view of a commonly used software practice. In Royces original waterfall model, the following phases are followed in order: 1. Requirements specification 2. Design 3. Construction (AKA implementation or coding) 4. Integration 5. Testing and debugging (AKA Validation) 6. Installation 7. Maintenance SDLC Systems Development Life Cycle (SDLC) is a process used by a systems analyst to develop an information system, including requirements,validation, training, and user (stakeholder) ownership. Any SDLC should result in a high quality system that meets or exceeds customer expectations, reaches completion within time and cost estimates, works effectively and efficiently in the current and planned Information Technology infrastructure, and is inexpensive to maintain and cost-effective to enhance.Computer systems are complex and often (especially with the recent rise of Service-Oriented Architecture) link multiple traditional systems potentially supplied by different software vendors. To manage this level of complexity, a number of SDLC models or methodologies have been created, such as waterfall; spiral; Agile software development; rapid prototyping; incremental; and synchronize and stabilize. SDLC models can be described along a spectrum of agile to iterative to sequential. Agile methodologies, such as XP and Scrum, focus on lightweight processes which allow for rapid changes along the development cycle.

How Sociology Defines Social Oppression

How Sociology Defines Social Oppression Social oppression is a concept that describes the relationship between two categories of people in which one benefits from the systematic abuse and exploitation of the other. Because social oppression is something that occurs between categories of people, it should not be confused with the oppressive behavior of individuals. In cases of social oppression, all members of the dominant and subordinate groups are involved, regardless of individual attitudes or behavior. How Sociologists Define Oppression Social oppression refers to oppression that is achieved through social means and that is social in scope- it affects whole categories of people. This kind of oppression includes the systematic mistreatment, exploitation, and abuse of a group (or groups) of people by another group (or groups). It occurs whenever one group holds power over another in society through the control of social institutions, along with societys laws, customs, and norms. The outcome of social oppression is that groups in society are sorted into different positions within the social hierarchies of race, class, gender, sexuality, and ability. Those in the controlling, or dominant group, benefit from the oppression of other groups through heightened privileges relative to others, greater access to rights and resources, a better quality of life, and overall greater life chances. Those who experience the brunt of oppression have fewer rights, less access to resources, less political power, lower economic potential, worse health and higher mortality rates, and lower overall life chances. Groups that experience oppression within the United States include racial and ethnic minorities, women, queer people, and the lower classes and the poor. Groups that benefit from oppression in the U.S. include white people (and sometimes light-skinned racial and ethnic minorities), men, heterosexual people, and the middle and upper classes. While some people are conscious of how social oppression operates in society, many are not. Oppression persists in large part by camouflaging life as a fair game and its winners as simply harder working, smarter, and more deserving of lifes riches than others. While not all of the people in dominant groups actively participate in sustaining oppression, they all ultimately benefit from it as members of society. In the U.S. and many other countries, social oppression has become institutionalized, meaning it is built into how our social institutions operate. Oppression is so normalized that it does not require conscious discrimination or overt acts of oppression to achieve its ends. This does not mean that conscious and overt acts do not occur, but rather that a system of oppression can operate without them once the oppression itself has become camouflaged within the various aspects of society. Components of Social Oppression Social oppression is produced through forces and processes that permeate all aspects of society. It is the result not only of peoples values, assumptions, goals, and practices but also of the values and beliefs reflected in organizations and institutions. Sociologists view oppression as a systemic process that is achieved through social interaction,  ideology, representation, social institutions, and the social structure. The processes that result in oppression operate at both the macro and micro levels. At the macro level, oppression operates within social institutions, including education, media, government, and the judicial system, among others. It also operates through the social structure itself, which organizes people into hierarchies of race, class, and gender. At the micro level, oppression is achieved through social interactions between people in everyday life, in which biases that work in favor of dominant groups and against oppressed groups shape how we see others, what we expect from them, and how we interact with them. What ties oppression at the macro and micro levels together is the dominant ideology- the sum total of values, beliefs, assumptions, worldviews, and goals that organize the way of life as dictated by the dominant group. Social institutions reflect this groups perspectives, experiences, and interests. As such, the viewpoints, experiences, and values of oppressed groups are marginalized and not incorporated into how social institutions operate. People who experience oppression on the basis of race or ethnicity, class, gender, sexuality, or ability often internalize the ideology that produces the oppression. They may come to believe, as society suggests, that they are inferior to and less worthy than those in dominant groups, and this, in turn, may shape their behavior. Ultimately, through this combination of macro- and micro-level means, oppression produces widespread social inequalities that disadvantage the vast majority for the benefit of the few.