Thursday, September 5, 2019
Three Information Systems Development Methods Information Technology Essay
Three Information Systems Development Methods Information Technology Essay Information system in this present period is been used by organisations, institutions, businesses and many industries. Information system development method is a general technique and procedures that is been followed in stages by system developers in the process of building a system. However, there are different types of information system development method which will be stated later in the report. The main aim of this report is to briefly compare three types of information systems development methods (ISDM) out of the several types of ISDM that exist which will be stated later in the report. Although, this report is more interested in the common methods that are mostly used such as waterfall method, spiral method and systems development life cycle method. In addition to the compared method this report has also adopted six related topics that are connected and interrelated to the information system development method. These six topics include information systems development method, types of information system development methodologies, difference between software development methodology (SDM) and SDLC, difference between system analysis and system design and introduction to project management. The Waterfall Method The waterfall information system development method is one of the easiest and straight forward information systems development method that talks about series of activities in the others of requirement, design, implementation, verification, and maintenance which are done in stages were each stage of the activity stated have to be hundred percent accomplished before the following section can be done (Davidson, 2002). In addition, Cadle Yeates (2004, pp. 77-78) also explained that the end product of each section of the waterfall method is used as an inputs to the product of the following stage as a result it does not permit you to review the previous stage once it is crossed just like the way water flows sequentially. Consequently, Hurst (2007) also analyzed that the waterfall information systems development method has been argued by many to be a bad method because it is not possible for a project to get one stage fully completed and corrected before making ahead to the following stage . However, Hughes et al (2004) one of the biggest advantages the waterfall method has over spiral and system development life cycle is that its make good use of time in terms of management, very easy to manage and it is mostly used for smaller project were all requirements are known. Though, it also has some drawbacks which include high level of risk, been disciplined in completing each stage of the activities in the model. The series of activities in the waterfall method is shown in the diagram below. Fig 1: Waterfall model The Spiral Method This is another type of information systems development method just like the waterfall and the system development life cycle method that also has series of activities that have to be done one after the other but in a different approach. The spiral method combines the important features of both the waterfall method and the prototyping method and most concerned about risk analysis (Dawson, 2005). Although, the spiral method has four stages compared to the waterfall and system development life cycle method which is in the stated order, determine objective, identify and resolve risk, development and testing then finally plan the next execution. All these levels that are mentioned are constantly repeated over and over again section by section until all the difficulties of the waterfall method are rectify. However, some of it advantages is that it is not use for minor project, it takes a very long time to be completed and also it is very expensive to manage. Similarly, it also has some limitations which include, controlling high level of risk analysis in a system development and also used for project were all requirement are complex. Thus it could be concluded that the spiral information system development method is mostly used for larger and complicated system development where the entire requirements are very difficult to understand compared to the waterfall and system development life cycle method. A diagram showing how the spiral method works is shown below: Fig 2: Spiral model. System Development Life Cycle (SDLC) Method This is also another type of information system development method similar to the waterfall and the spiral method with series of activities followed in a circular other in stages through which every developer, database designer and project manager pass through as to develop an information system (Radack, 2009). The system development life cycle method is the overall cognitive process that takes place in the development of information systems in a gradual manner until there is an achievement of the best quality in the development of a system. In addition, (Dawson, 2005) also stated that the system development life cycle is the general process of developing, implementing, and constructing information systems through a multistep process from Requirement, Design, Build, Test and maintenance. However, some its features includes dividing stages into sub stages for easy management and also gives a room for going back to stage when there is a problem unlike the waterfall information system development method. It also has some limitations which includes not meeting the users requirements, not been stable, having lack of control and also having problems with documenting. On this basis, it can be inferred that the SDLC is a procedure that every information system development must pass through even if each of them emphasizes on different part of the five stages of the SDLC method. Below is a diagram that shows how the stages in the SDLC take place in a circular form moving from one stage to the other. Fig 3: System development life cycle model Information systems development method. A brief introduction of information system development method has been given at the beginning of this report but it will be better to look as the definition its self. Information systems development method (ISDM) is defined as: A collection of procedures, techniques, tools and documentation aids which help the system developers in their efforts to implement a new information system. A methodology will consist of phases, themselves consisting of sub phases, which will guide the systems developers in their choice of the techniques that might be appropriate at each stage of project and also help them plan, manage, control and evaluate information systems project (Avison Fitzgerald, 2006, p. 24). It is clear therefore that the information systems development methods concentrate on the general process of development. Categories of Information System Development Methods. Different categories of information systems development methods are considered in the outgrowth of developing an application. Although, every information systems development method has its own special way of approaching each stage of the ISDM process. Thus, the information system development method that exist include: Agile, SSM, SSADM, RAD, PRINCE, Spiral, SDLC, Waterfall, Object oriented, XP etc (Banks Wood-Harper, 2005). However, this information systems development method follows the same procedure known as life cycle. Difference between Software development methodology SDM and SDLC. Britton Doake (2006) differentiated the different between a software development methodology and system development life cycle as, a software development life cycle is mainly concerned about the overall development model of a system with different level of constructing procedures in addition to the sections and protocols that has to be used in completing each sections whereas a system development life cycle is strictly a sequence of activities that are carried out by designers and analyst to produced and implement an information system. Difference between System Analysis and System Design. Shelly (2008, p. 22) explain that System Analysis is the process of collecting or gathering all useful and possible requirement regarding the information system to be developed from the users and also determining how it will be put into the development of the system whereas System design is the process whereby all the requirement that was collected and analyzed during the system analysis stage is put together in the design of the system. Introduction to Project Management According to Kerzner (2006, pp.55-58), Project management can be defined as every unit of activity put to consideration or executed in achieving a common goal or task and the measurement of project success based on time, cost, and quality performance or scope critical success factors. However, information system development or project must be well managed in other to be successful. This is where project management is involved. In addition, project management deals more with the management of a project emphasizing more on time, cost and scope which are the most important issues in a project. Therefore, the main reason for managing a project is to present a well documented work or system development within a specific time in a full flesh package and of the best quality. Conclusion In conclusion, this report has been able to make a good comparison of three types of information system development methods which were waterfall, spiral and system development life cycle methods. In addition, it has also been able to include and discussed six topics that were related to information system development method.