phases of sdlc in system analysis and design
Systems development life cycle The SDLC adheres to important phases that are essential for developers, such as planning, analysis, design, and implementation, and are explained in the section below. It includes evaluation of present system, information gathering, feasibility study and request approval. A number of SDLC models have been created: waterfall, fountain, spiral, build and fix, rapid prototyping, incremental, synchronize and stabilize. The oldest of these, and the best known, is the waterfall model: a sequence of stages in which the output of each stage becomes the input for the next. These stages can be characterized and divided up in different ways, including the following:[7]
Strategic Defense Initiative The Strategic Defense Initiative (SDI) was a proposed missile defense system intended to protect the United States from attack by ballistic strategic nuclear weapons (intercontinental ballistic missiles and submarine-launched ballistic missiles). The concept was first announced publicly by President Ronald Reagan on 23 March 1983.[1] Reagan was a vocal critic of the doctrine of mutual assured destruction (MAD), which he described as a "suicide pact", and he called upon the scientists and engineers of the United States to develop a system that would render nuclear weapons obsolete.