chap 3.pdf

Chapter 3: Overview of System Development Trần Thị Tuyết - 2023 Questions 1. Why should an organization develop a system? 2. Who should participate in a system development project? 3. How to plan for IS project? 4. What approaches are used to develop an IS project? 5. Factors affecting system dev...

Chapter 3: Overview of System Development Trần Thị Tuyết - 2023 Questions 1. Why should an organization develop a system? 2. Who should participate in a system development project? 3. How to plan for IS project? 4. What approaches are used to develop an IS project? 5. Factors affecting system development success? Typical reasons to initiate system development Participants in system development People who, either themselves or through the organization they represent, ultimately benefit from the systems development project People who will interact with the system regularly. A professional specializing in analyzing and designing business systems A specialist responsible for modifying or developing programs to satisfy user requirements IS planning The term information systems planning refers to translating strategic and organizational goals into systems development initiatives Strategic plan The steps of IS planning Previously unplanned systems projects Develop overall objectives Identify IS projects Set priorities and select projects Develop IS planning document Set schedules and deadlines Analyze resource requirements Establishing objectives for system development • The overall objective of systems development is to achieve business goals, not technical goals, by delivering the right information to the right person at the right time. Performance objectives Cost objectives • The quality or usefulness of the output. • The accuracy of the output • The speed at which output is generated • The scalability of the resulting system • The risk of the system. • Development costs. • Costs related to the uniqueness of the system application. • Fixed investments in hardware and related equipment • Ongoing operating costs of the system Approaches to system development 1. Traditional system development life cycle 2. Prototyping 3. Rapid Application Development, Agile Development, Joint Application Development 4. The End-user Systems Development 5. Outsourcing and On-demand computing Traditional system development life cycle Systems investigation: problems and opportunities are identified and considered in light of the goals of the business. System analysis: Studying existing systems and work processes to identify strengths, weaknesses, and opportunities for improvement. The major outcome of systems analysis is a list of requirements and priorities System design: defines how the information system will do what it must do to obtain the problem solution. System implementation: involving the creation or acquisition of various system components detailed in the systems design, assembling them, and placing the new or modified system into operation Systems maintenance and review : ensures the system operates and modifies the system so that it continues to meet changing business needs. Systems development life cycle (SDLC) Traditional system development life cycle Prototyping • Prototyping is an iterative approach to systems development. Prototyping (cont) Rapid Application Development and Joint Application Development • Rapid application development (RAD) A systems development approach that employs tools, techniques, and methodologies designed to speed application development. • Joint application development (JAD) A process for data collection and requirements analysis in which users, stakeholders, and IS professionals work together to analyze existing systems, propose possible solutions, and define the requirements of a new or modified system. Agile development or extreme programming (XP) allows the systems to change as they are being developed. Agile development requires frequent face-to-face meetings with the systems developers and users as they modify, refine, and test how the system meets users’ needs and what its capabilities are. Advantages and Disadvantages of RAD The End-user Systems Development • The term end-user systems development describes any • • • • • systems development project in which business managers and users assume the primary effort User-developed systems range from the very small (such as a software routine to merge form letters) to those of significant organizational value (such as customer contact databases for the Web). With end-user systems development, managers and other users can get the systems they want without having to wait for IS professionals to develop and deliver them. Some end users don’t have the training to effectively develop and test a system. Some end-user systems are also poorly documented. Some end users spend time and corporate resources developing systems that were already available Outsourcing and On-Demand Computing Outsourcing and On-Demand Computing (cont.) Reducing costs, Obtaining stateof-the-art technology, Eliminating staffing and Losing internal expertise Being difficult to achieve a competitive advantage Security Comparison of developed and off-the-shelf software Factors affecting system development success 1. Degree of Change 2. Quality and Standards 3. Use of Project Management Tools 4. Use of Computer-Aided Software Engineering (CASE) Tools 5. Object-Oriented Systems Development Degree of change • The degree of change can greatly affect the probability of a project’s success. Managing Change Managing change requires the ability to recognize existing or potential problems (particularly the concerns of users) and deal with them before they become a serious threat to the success of the new or modified system. Common problems: • Fear that the employee will lose his job, power, or influence within the • • • • • organization Belief that the proposed system will create more work than it eliminates Reluctance to work with “computer people” Anxiety that the proposed system will negatively alter the structure of the organization Belief that other problems are more pressing than those solved by the proposed system or that the system is being developed by people unfamiliar with “the way things need to get done” Unwillingness to learn new procedures or approaches Quality and Standards Use of Project Management Tools • Project schedule is a detailed description of what is to be done. Each project activity, the use of personnel and other resources, and expected completion dates are described • Project milestone is a critical date for the completion of a major part of the project. The completion of program design, coding, testing, and release are examples of milestones for a programming project. • Project deadline is the date the entire project is to be completed and operational—when the organization can expect to begin to reap the benefits of the project • Critical path consists of all activities that, if delayed, would delay the entire project. These activities have zero slack time. Any problems with critical-path activities will cause problems for the entire project. • Program Evaluation and Review Technique (PERT) creates three time estimates for an activity: shortest possible time, most likely time, and longest possible time • Gantt chart is a graphical tool used for planning, monitoring, and coordinating projects; it is essentially a grid that lists activities and deadlines. Use of Computer-Aided Software Engineering (CASE) Tools • CASE tools automate many of the tasks required in a systems development effort and encourage adherence to the SDLC, thus instilling a high degree of rigor and standardization to the entire systems development process. Advantages and Disadvantages of CASE Object-Oriented Systems Development (OOSD) • OOSD is an approach to systems development that combines the logic of the systems development life cycle with the power of objectoriented modeling and programming. • OOSD tasks: • Identifying potential problems and opportunities within the organization that would • • • • • be appropriate for the OO approach. Defining what kind of system users require. Designing the system. Programming or modifying modules. Evaluation by users. Periodic review and modification.