Systems Development Life Cycle - Essay Example

Systems Development Life Cycle The system development life cycle is delineated as a conceptual model that is used inthe management of various projects, defines and explains the different stages that are involved in the information system development project, from the initial stages to the completed application. This paper regards system as a set of interdependent or various interacting components that forms the integrated whole. The below steps are involved in the development of a system; 1. Preliminary investigation. The most important task in the designing of a system is the recognition of the problem. It entails looking at the current operations and system and analyze if it meets the organizations demand. The analyst therefore makes the survey by gathering all the required information for the designing of the program. It will also give the picture of what the system. A system analyst will then prepare a proposal that contains the findings of the current study and the recommendations to overcome some of the problems and limitations of the present study. (Noopur, 2012) Feasibility study After getting the proposal with recommendations, a feasibility study is carried out. It is basically the test of the proposed system in terms of meeting the requirements of the use, workability, cost and the effective use of the resources. The main aim at this stage is to achieve the scope and not to solve a problem. It is at this study when the cost benefit analysis is done with high accuracy. Generally it considers; technical, economic return, non-economic return, legal and ethical, schedule and operational aspects of the new system. Analysis During this stage, the project team determines the requirements of the end user besides refining the project goals into succinct operations and functions of the new system. It is usually done with the assistance of the client focus groups which gives an explanation of their needs and expectations for the new system and how it will perform upon completion. All the user requirements will be documented by the project team and they will the sign-off from the management and client to move forward with the designing of the system. Some of the main activities at this stage include gathering information; building rapport and trust with client; documenting existing system, developing preliminary model and verifying requirements. The expected outputs include system requirements documents; detailed scope of the project and report deliverables besides the process and data models. System Design This is the architectural phase of the system design. The data processing flow is developed into charts and the project team determines the logical design and structure for the flow of the data and storage. The system design helps in the specification of hardware and the requirements system. It also helps in the definition of the overall system architecture. Some of the activities involves the determination of the technical systems configuration, determination of the structure of data, determination of buy or make decision; prototype and the plan for system conversation. The key output expected includes report on system architecture; plan and chart of system conversation; pseudo-code; data structure diagrams and the prototypes. System Coding Upon the receipt of the design documents, the work is divided into units/modules as actual coding begins. Coding is the main focus of the developer at this stage. At this stage, the analyst translates the programs or code in a manner that they become machine in a readable. It is quite tedious exercise and has room for errors. It is the longest phase of the system design. (Igor 1998) Testing After the code shave been developed, it is tested against the requirements to ensure that the designed system is solving the problems as gathered during the preliminary investigations. During this stage, the unit, integration, system and acceptance testing is done. Testing can be done by the real users or the team of specialized personnel in the field. Implementation After the user has accepted the system, the phase of implementation will begin. It is a stage where theory is translated into practice. The designed system is installed into user’s computers. After loading the system, onto the computers, the training session will begin with some key topics being how to execute the package; how to enter data, how to process data, how to take out reports and how to get help when stuck. The key outputs expected include satisfied users and the modification of the requests. Maintenance Maintenance of any system is important as it helps in reducing any error in the system and during its working life to any variation in the working environment. It has always been noted that at least there will be errors in the system that should be dealt with to ensure smooth operations. The system should always be reviewed from time to time to deal with any possible error that might interfere with the operations. Review helps in knowing the system capabilities, required changes or additional requirements and the performance of the system. (Najjar, 1990) Why the Enhanced Waterfall Model is a better Waterfall approach was the first system development life cycle to be used by a myriad of software engineers across the globe to ensure the successful implementation of a project. In this approach which is also referred to as the linear sequential life cycle model, every phase starts only after the completion of the previous phase. Phases do not overlap. It is simple to use and understand. Enhanced model involves the verification and validation between different phases of the traditional waterfall medal. There are a number of reasons of using Enhanced Waterfall and not the traditional waterfall model which is discussed below; The enhanced waterfall model is easier to implement and the resources required are minimal; it has high level of visibility given that the output is generated after each stage. The client is able to have information on the progress of the project. (Obrien & Marakas, 1989) The model is good because the deadlines can be set at every stage for the completion besides the fact that the evaluation can be done from time to time making it possible to have necessary adjustments and to check whether the project is going on as planned with different milestones. It is also advantageous given that it provides a template that makes it possible to place various phases and processes to be taken such as planning, analysis, designing, coding, testing and the maintenance. The stages help in the classification and clarification of jobs and roles of various team members during the entire project life. It is also preferred on projects where the consideration of quality is important than the cost that is likely to be incurred. It is preferred because of the high chances of getting a good system in time. (Obrien & Marakas, 1989) Data flow diagram is delineated as the graphical representation of data that flows in the entire information system. It can also be used in the visualization of the entire processing of data. The flow looks at the system as a function that helps in the transformation of the input into the required output. The below is level-0 Data flow diagram and also level-0 Data flow diagram explaining the flow of data in the system and the persons who are involved. Level 1 Entity Relationship Diagram (ERD) This is a graphical tool that is used in data modeling and mainly used in the design of a database. It is a simple but logical representation of a data base that identifies entities and concepts existing in the system and the existing complex relationship between the entities. The below us an example of Entity Relationship Diagram (ERD) for the management of a hotel (Najjar, 1990) References Najjar, L. J. 1990, Rapid prototyping (TR 52.0020). Atlanta, GA: IBM Corporation. Igor Hawryszkiewycz. 1998, Introduction to System Analysis & Design, The Development Process, pg120 - 136 Ch 7 Prentice Hall- Australia Noopur D., 2012, Secure Software Development Life Cycle Processes, Carnegie Mellon University, pages 39, 2012 http://www.sei.cmu.edu/reports/05tn024.pdf Obrien A. O & Marakas .M. 1989, Management Information Systems, Introduction to Information Systems, pg27 - 32 Ch1 McGraw-Hill Co Post. G & Anderson. D 2006, Management Information Systems, Organizing Business Solutions, pg 448 - 459 Ch 4 McGraw-Hill Co- New York Read More