Introduction to System Analysis and Design

1. System Analysis and Design Introduction to System Analysis and Design - Dr. Mahmoud Abu-Arra - Mr. Ahmad Al-Ghoul

2. Learning Objectives • Describe the systems development life cycle • Discuss Systems Development Guidelines System Analysis and Design Introduction to SAD

3. Introduction • Systems development life cycle (SDLC) is a common methodology for system development in many organizations; it features several phases that mark the progress of the systems analysis and design effort • Every text book and information systems development organization uses a slightly different life cycle model • SDLC involves a series of phases. • You can think about SDLC like constructing a building. First, you would list specific objectives for the project. Then you might hire an architect to present an overall concept and create a set of drawings to show how the building will fulfill your objectives. Later, you would need detailed blueprints for the workers. When the building is done, you would check it out, test everything, turn it over to the new occupants, and make sure they are satisfy with the results. System Analysis and Design Introduction to SAD

4. The Systems Development Life Cycle operation, security and support Design and Implementation Planning and Analysis An idea Time System Analysis and Design Introduction to SAD

5. The Systems Development Life Cycle • SDLC is Series of steps used to manage the phases of development for an information system • SDLC used to plan and manage the systems development process • The life cycle can be thought as a circular process in which the end of the useful life of one system leads to the beginning of anther project that will develop a new version or replace an existing system altogether • SDLC is not necessary to be sequentially ordered set of phases, the specific steps and their sequence are meant to be adapted as required for a project • In a SDLC you can complete some activates in one phase in parallel with some activates of anther phase System Analysis and Design Introduction to SAD

6. The Systems Development Life Cycle • In some cases the SDLC is iterative; that is, phases are repeated as required until an acceptable system is found • The SDLC used in an organization is an orderly set of activates conducted and planned for each development project • Each activity or phase in the SDLC has specific outcomes that feed important information to other phases System Analysis and Design Introduction to SAD

7. The Systems Development Life Cycle • Each of the phases include a set of steps, which rely on techniques that produce specific document files that provide understanding about the project. • Individual companies use customized life cycles System Analysis and Design Introduction to SAD

8. The Systems Development Life Cycle • Traditionally pictured as a waterfall model • In waterfall model the result of each phase, which is called end product, flaws sequentially into the next phase • The adjacent phases interact, as shown by dotted lines System Analysis and Design Introduction to SAD

9. The Systems Development Life Cycle • Alternative model • In the alternative model of the SDLC, planning, analysis, and design interact continuously, followed by implementation and operation and support • interactive model depicting real world practice and the constant dialog among users, managers, and systems developers System Analysis and Design Introduction to SAD

10. The Systems Development Life Cycle • System development life cycle includes the following steps: • Systems planning • Systems analysis • Systems design • Systems implementation • Systems operation, support, and security Planning Analysis Systems Operation and Support Design Implementation System Analysis and Design Introduction to SAD

11. The Systems Development Life Cycle • Systems planning • Purpose is to identify the nature and scope of the business opportunity or problem • Systems request – begins the process & describes problems or desired changes in an information system or business process • Systems planning includes preliminary investigation to identify the nature and scope of the business opportunity or problem. The outcome of preliminary investigation will affect the entire development process. A key part of the preliminary investigation is a feasibility study that reviews costs and benefits and recommends a course of action based on operational, technical, economic and time factors. System Analysis and Design Introduction to SAD

12. The Systems Development Life Cycle • Systems Analysis • Purpose is to build a logical model of the new system • The analysis phase answers the questions of who will use the system, what the system will do, and where and when it will be used. • During this phase the project team investigates any current systems, identifies improvement opportunities, and develops a concept for the new system. • First step is requirements modeling, where you investigate business processes and document what the new system must do. To understand the system, you perform fact-finding using techniques such as interviews, surveys, document review, observation, and sampling • End product is the System requirements document which describes management and user requirements, costs, and benefits, and outline alternative development strategies. System Analysis and Design Introduction to SAD

13. The Systems Development Life Cycle • Systems Design • In this phase the designer decided how the system will operate, in terms of the hardware, software, and network infrastructure; the user interface, forms, and reports that will be used; and the specific programs, databases, and files that will be needed. • Purpose is to create a blueprint that will satisfy all documented requirements • Identify all outputs, inputs, and processes • Avoid misunderstanding through manager and user involvement • End product is system design specification • Logical Design • Concentrates on business aspects of the system • Physical Design • Technical specifications System Analysis and Design Introduction to SAD

14. The Systems Development Life Cycle • Systems Implementation • New system is constructed • Write, test, & document programs • File conversion occurs • Users, managers, IT staff trained to operate and support the system • System evaluation performed, to determine whether the system operates properly and if costs and benefits are within expectations. System Analysis and Design Introduction to SAD

15. The Systems Development Life Cycle • Systems Operation, Support, and security • New system supports operations • Maintenance changes correct errors or meet requirements • Enhancements increase system capability by provide new features and benefits • The objective during this phase is to maximize return on the IT investment • Security controls safeguard the system from both external and internal threats • A well-designed system will be secure, reliable, maintainable, and scalable so it can expand to meet new business requirements and volumes • After several years of operation, systems need extensive changes • SDLC ends with system replacement System Analysis and Design Introduction to SAD

16. Systems Development Guidelines • With experience as a system analyst, you will develop your own style and techniques. Although each project is different and have its constraints, rules, so you can decide which methods and technique you will use, you should consider some basic guidelines as you build an information system. • Planning: • stick to an overall development plan • Involve users throughout the development process • Ensure that users are involved in the development process, especially when identifying and modeling system requirements • Listening is Very Important • The best system is the one that meets user needs most effectively. When you interact with users, you must put aside any preconceived notations and listen closely System Analysis and Design Introduction to SAD

17. Systems Development Guidelines • Create a Time Table with Major Milestones • Identify major milestones for project review and assessment. At those milestones, managers and systems developers must decide whether to proceed with the project, redo certain tasks, return to earlier phase, or terminate the project • Identify Interim Checkpoints • Establish interim checkpoints between major milestones to ensure that the project remains on schedule • Remain Flexible • System development is a dynamic process, and overlap often exists between the phases of system planning, analysis, design, and implementation • Develop Accurate Cost and Benefit Information • Provide accurate and reliable cost estimation and benefit information to managers at start of each phase System Analysis and Design Introduction to SAD

18. Sequence Summary • In this Sequence we have • Described the systems development life cycle • Distinguished between Traditional SDLC as a waterfall model and the Alternative SDLC model • Defined system planning, system analysis, system design, system implementation, System Operation, Support, and security • Discussed systems development guidelines System Analysis and Design Introduction to SAD

19. Reference [1] System Analysis and Design, Sixth Edition Authors: Gary B. Shelly, Thomas J. Cashman and Harry J. Rosenblatt , Publisher: SHELLY CASHMAN SEWIES. [2] Modern Systems Analysis and Design Third Edition Authors: Jeffrey A. Hoffer , Joey F. George, Joseph S. Valacich Publisher: prentice hall [3] System Analysis and Design, 3rd Edition Authors: Dennis, Wixom, & Roth Publisher: John Wiley & sons System Analysis and Design Introduction to SAD