Q3 What is systems analysis and systems design Discuss in detail?

Answer 1

Ans: INTRODUCTION Systems are created to solve problems. One can think of the systems approach as an organized way of dealing with a problem. In this dynamic world, the subject System Analysis and Design, mainly deals with the software development activities. Defining A System A collection of components that work together to realize some objective forms a system. Basically there are three major components in every system, namely input, processing and output. In a system the different components are connected with each other and they are interdependent. For example, Human body represents a complete natural system. We are also bound by many national systems such as political system, economic system, educational system and so forth. The objective of the system demand that some output is produced as a result of processing the suitable inputs. System Analysis Assuming that a new system is to be developed, the next phase is system analysis. Analysis involved a detailed study of the current system, leading to specifications of a new system. Analysis is a detailed study of various operations performed by a system and their relationships within and outside the system. During analysis, data are collected on the available files, decision points and transactions handled by the present system. Interviews, on-site observation and questionnaire are the tools used for system analysis. Using the following steps it becomes easy to draw the exact boundary of the new system under consideration: Keeping in view the problems and new requirements Workout the pros and cons including new areas of the system All procedures, requirements must be analysed and documented in the form of detailed data flow diagrams (DFDs), data dictionary, logical data structures and miniature specifications. System Analysis also includes sub-dividing of complex process involving the entire system, identification of data store and manual processes. The main points to be discussed in system analysis are: Specification of what the new system is to accomplish based on the user requirements. Functional hierarchy showing the functions to be performed by the new system and their relationship with each other. Function network which are similar to function hierarchy but they highlight the those functions which are common to more than one procedure. List of attributes of the entities - these are the data items which need to be held about each entity. System Design Based on the user requirements and the detailed analysis of a new system, the new system must be designed. This is the phase of system designing. It is a most crucial phase in the development of a system. Normally, the design proceeds in two stages : i) Preliminary or general design ii) Structure or detailed design Preliminary or general design: In the preliminary or general design, the features of the new system are specified. The costs of implementing these features and the benefits to be derived are estimated. If the project is still considered to be feasible, we move to the detailed design stage. Structure or Detailed design: In the detailed design stage, computer oriented work begins in earnest. At this stage, the design of the system becomes more structured. Structure design is a blue print of a computer system solution to a given problem having the same components and inter-relationship among the same components as the original problem. Input, output and processing specifications are drawn up in detail. In the design stage, the programming language and the platform in which the new system will run are also decided. There are several tools and techniques used for designing. These tools and techniques are: Flowchart, Data flow diagram (DFDs), Data dictionary, Structured English, Decision table Decision tree There is no such discipline or activity as "analysis and design". Furthermore, a clear distinction between the two is absolutely essential to any large software development project. It's certainly possible, although uncommon, for a single individual to be skilled at both systems analysis and system design. It is then perfectly acceptable for him or her to do systems analysis some of the time and system design some of the time. It is never acceptable, however, to do both or some sort of mixture of the two at the same time. The introduction of structured analysis in the 1970's came about partly as a reaction against the then common practice of mixing the two. Why did so many projects mix the analysis and design? Partly because many systems analysts were former programmers, who felt more comfortable designing files and programs than determining and documenting what the users needed. "the products of development, including data-flow diagrams, are not ends in themselves; they should be viewed simply as tools along the way that aid the developer's comprehension of the problem and its implementation." That emphasis on the developer is echoed in countless presentations in which it's clear that the speaker views the UML exclusively as a tool for developers to use in communicating among themselves. When questioned about communicating with the sponsoring end users, they rarely have a good answer. Some go as far as to suggest that the systems analyst may need to prepare a separate package of documentation aimed at the non-technical audience. That, of course, is an invitation to put all the project's eggs in a basket where omissions and inconsistencies won't become obvious until the late stages of the project. Mr. G. Lakshman Rao Rayagada