System Analysis and Design

IRJMST

Vol 5 Issue 5 [Year 2014]

ISSN 2250 – 1959

(0nline)

2348 – 9367 (Print)

System Analysis and Design

Jashanpreet Singh (B.tech student) Department of computer science Guru Nanak Dev University Amritsar Punjab ABSTRACT System analyst gives the system development project meaning and directional. To understand system development we need to recognize that a candidate system has a life cycle, just like a living system or a new product. In the present paper I have defined the system and its phases to develop a system. INTRODUCTION To operate system work one needs to understand the systems concept and how organizations operate as a system and then design appropriate computer based system that will meet organization requirements. It is actually a customized approach to use the computers for problem solving. System analysis and design have many stages recognition of the need for change, feasibility study, analysis of the present system, design of the candidate system, testing and implementation of the system and post implementation. These stages of the system analysis and principles of software design are discussed in detail. DEFINING SYSTEM ANALYSIS System analysis is the application of the systems approach to problem solving using computers. The term system is derived from the Greek word systema which means an organized relationship among functioning units or components. A system exists because it is designed to achieve one or more adjectives. Definition of a system suggests some characteristics that are present in all systems organization, interaction, interdependence, integration and a central objective. 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. A collection of components that work together to realize some objective forms a system. International Research Journal of Management Science & Technology http://www.irjmst.com

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IRJMST

Vol 5 Issue 5 [Year 2014]

ISSN 2250 – 1959

(0nline)

2348 – 9367 (Print)

Basically there are three major components in every system, namely input, processing and output. Our system defines the different components that are connected to each other and how they are interdependent. The objective of the system demands that some output is produced as a result of processing the suitable inputs. SYSTEM DEVELOPMENT LIFE CYCLE System development life cycle is an organizational process of developing and maintaining systems. It helps in establishing a system project plan, because it gives overall list of processes and sub-processes required developing a system. System development life cycle means combination of various activities. In other words, various activities put together are referred as system development life cycle. In the System Analysis and Design terminology, the system development life cycle means software development life cycle. System analysis and design are keyed to the system life cycle. We must know the problem before solving it. The basis for a system is recognition of need for improving the system or a procedure. The different phases of software development cycle • Feasibility study • System analysis • System design • Coding • Testing • Implementation • Maintenance FEASIBILITY A feasibility study is a test of a system proposal according to its workability, impact on the organization, ability to meet user needs, and effective use of resources. It focuses on three major questions: 1. What are the user‟s demonstrable needs and how does a candidate system meets them? 2. What resources are available for given candidate system? Is the problem worst solving? 3. What is the likely impact of the candidate system on the organization? How well does it fit within the organization‟s master MIS plan? The result of the feasibility study is a formal proposal. The proposal summarizes what is known and what is known and what is going to be done. It consists of the following: International Research Journal of Management Science & Technology http://www.irjmst.com

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IRJMST

Vol 5 Issue 5 [Year 2014]

ISSN 2250 – 1959

(0nline)

2348 – 9367 (Print)

1. Statement of the problem. 2. Summary of finding and recommendations. 3. Details of the finding. 4. Recommendation and conclusion. After the proposal is reviewed by management, it becomes a formal agreement the paves the way for actual design and implementation. This is a crucial decision point in the life cycle. Many projects die here whereas the more promising ones continue through implementation. Changes in the proposal are made in writing, depending on the complexity, size, and cost of the project. It is simply common sense to verify changes before committing the project to design. ANALYSIS Analysis is a detailed study of the various operations performed by a system and their relationships within and outside of the system. A key question is: What must be done to solve the problem? One aspect of analysis is defining the boundaries of the system and determining whether or not a candidate system should consider other related systems. During analysis, data are collected on the available files, decision points, and transactions handled by the present system. The interview is a commonly used to tool in analysis. It requires special skills and sensitivity to the subjects being interviewed. Bias in data collection and interpretation can be a problem. Training, experience, and common sense are required for collection of the information needed to do the analysis. Once analysis is completed, the analyst has a firm understanding of what is to be done. The next step is to decide how the problem might be solved. Thus, in systems design, we move from the logical to the physical aspects of the life cycle. DESIGN The most creative and challenging phase of the system life cycle is system design. The term design describes a final system and the process by which it is developed. It refers to the technical specifications (analogous to the engineer‟s blueprints) that will be applied in implementing the candidate system. It also includes the construction of programs and program testing. The final report prior to the implementation phase includes procedural flowcharts, record layouts, report layouts and a workable plan for implementing the system. There are certain functions, the analyst perform while programs are being written. Operating procedure and documentations must be completed. Security and auditing procedures must also be developed. IMPLEMENTATION International Research Journal of Management Science & Technology http://www.irjmst.com

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IRJMST

Vol 5 Issue 5 [Year 2014]

ISSN 2250 – 1959

(0nline)

2348 – 9367 (Print)

The implementation phase is less creative than system design. It is primarily concerned with user training, site preparation, and file conversation. When the candidate system is linked to terminals or remote sites, the telecommunication network and tests of the network along with system is linked are also included under implementation. During the final testing, user acceptance is tested, user acceptance is tested, training may be required. Conversion usually takes place at about the same time the user is being trained or later. In the extreme, the programmer is falsely viewed as someone who ought to be isolated from other aspects of the system development. Programming is itself design work, however. The initial parameters of the candidate system should be modified as a result of programming efforts. Programming provides a „reality test’ for the assumptions made by the analyst. It is therefore a mistake to exclude programmers from the initial system design. POST IMPLEMENTATION AND MAINTENANCE After the installation phase is completed and the user staff is adjusted to the changes created by the candidate system, evaluation and maintenance begin. Like any system, there is an aging process that requires periodic maintenance of hardware and software. If the new information is inconsistent with the design specification, then changes have to be made. Hardware also requires periodic maintenance to keep in tune with design specifications. The importance of maintenance is to continue to bring the new system to standards. User‟s priorities, changes in organization requirements, or environmental factors also call for system enhancements. SOFTWARE DESIGN Software design is both a process and a model. The design process is a sequence of steps that enable the designer to describe all aspects of the software to be built. It is important to note, however, that the design process is not simply a cookbook. Creative skill, past experience, a sense of what makes “good” software and an overall commitment to quality are critical success factors for a competent design. The design model is the equivalent of an architect‟s plans for a house. It begins by representing the totality of the thing to be built (e.g., a three-dimensional rendering of the house) and slowly refines the thing to provide guidance for constructing each detail (e.g., the plumbing layout). Similarly, the design model that is created for software provides a variety of different views of the computer software. Basic design principles enable the software engineer to navigate the design process. The principles for software design, which have been adapted and extended are in the following list: International Research Journal of Management Science & Technology http://www.irjmst.com

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The design process should not suffer from “tunnel vision.” A good designer should consider alternative approaches, judging each based on the requirements of the problem, the resources available to do the job. The design should be traceable to the analysis model. Because a single element of the design model often traces to multiple requirements, it is necessary to have a means for tracking how requirements have been satisfied by the design model. The design should not reinvent the wheel. Systems are constructed using a set of design patterns, many of which have likely been encountered before. These patterns should always be chosen as an alternative to reinvention. Time is short and resources are limited! Design time should be invested in representing truly new ideas and integrating those patterns that already exist. The design should “minimize the intellectual distance” between the software and the problem as it exists in the real world. That is, the structure of the software design should (whenever possible) mimic the structure of the problem domain. The design should exhibit uniformity and integration. A design is uniform if it appears that one person developed the entire thing. Rules of style and format should be defined for a design team before design work begins. A design is integrated if care is taken in defining interfaces between design components. The design should be structured to accommodate change. The design concepts discussed in the next section enable a design to achieve this principle. The design should be structured to degrade gently, even when aberrant data, events, or operating conditions are encountered. Well- designed software should never “bomb.” It should be designed to accommodate unusual circumstances, and if it must terminate processing, do so in a graceful manner. Design is not coding, coding is not design. Even when detailed procedural designs are created for program components, the level of abstraction of the design model is higher than source code. The only design decisions made at the coding level address the small implementation details that enable the procedural design to be coded. The design should be assessed for quality as it is being created, not after the fact. A variety of design concepts and design measures are available to assist the designer in assessing quality. The design should be reviewed to minimize conceptual (semantic) errors. There is sometimes a tendency to focus on minutiae when the design is reviewed, missing the forest for (omissions, ambiguity, and inconsistency) have been addressed before worrying about the syntax of the design model.

International Research Journal of Management Science & Technology http://www.irjmst.com

Page 118

IRJMST

Vol 5 Issue 5 [Year 2014]

ISSN 2250 – 1959

(0nline)

2348 – 9367 (Print)

REFERENCE 1. System analysis and design, Elias M. Awad 2. Ralph, P. and Wand, Y. (2009). A proposal for a formal definition of the design concept 3. Freeman, Peter; David Hart (2004). A Science of design for softwareintensive systems.

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