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System Analysis

System Analysis

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System Analysis

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  1. System Analysis and Design System Analysis - Mr. Ahmad Al-Ghoul

  2. Learning Objectives • Describe systems analysis phase activities and the end product of the systems analysis phase • Describe the Unified Modeling Language (UML) • Describe Functional Decomposition Diagram ( FDD ) • Explain why analysts using models • Describe CASE tools, objectives, and types System Analysis and Design System Analysis

  3. Learning Objectives • List and describe system requirements, including outputs, inputs, processes, performance, and controls • Explain the importance of scalability • Define total cost of ownership (TCO) and explain the concept System Analysis and Design System Analysis

  4. Introduction • The overall objective of the systems analysis phase is to understand the proposed system, ensure that it will support business requirement, and build solid foundation of system development. • Systems Analysis Activities • The systems analysis phase includes three main activates • Requirements modeling • Data and process modeling • Development Strategies System Analysis and Design System Analysis

  5. Systems Analysis Phase Overview • requirements Modeling • Requirements modeling involves • Fact finding • Describing the current system and identification of the requirements for the new system which includes • Outputs: electronic or printed information produced by the system • Inputs: data that enters the system • Processes: the logical rules that are applied to transform the data into information • Performance: the system characteristics, speed, volume, capacity, availability, and reliability • Security: hardware, software, and procedural controls that protect the system and data from internal or external threats System Analysis and Design System Analysis

  6. Systems Analysis Phase Overview • Data and process modeling • Represent graphically system data and process using various techniques. • Development Strategies • Evaluation of alternative solutions • Preparation of the system requirements document • System requirements document is an overall design for the new system System Analysis and Design System Analysis

  7. Systems Analysis Phase Overview • Modeling tools and techniques • Modeling involves graphical methods and non-technical language that represent the system at various stages of development • There are various tools to describe business processes, requirements, and user interaction with the system System Analysis and Design System Analysis

  8. Modeling Tools and Techniques • Analysts using models to: • Concentrate on important features of the system, pay less attention to less important ones; • Able to respond to changes or changes in user’s requirements with low cost and risk; • Properly understand users’ environment and write documents in the same way that designers and programmers construct the system. System Analysis and Design System Analysis

  9. Modeling Tools and Techniques • CASE Tools ( computer-aided software engineering ) • CASE tools have been developed for internal use and for sale by several firms, including Oracle ( Designer), IBM ( Rational Rose ) • Automated software tool used by systems analysts to develop information systems • Used to support or automate activities throughout the systems development life cycle (SDLC) • CASE tools include diagramming tools for data flow diagrams and other graphical aids, screen and report design tools, and other special-purpose tools System Analysis and Design System Analysis

  10. Modeling Tools and Techniques • Objectives of CASE • Improve quality of systems developed • Increase speed of development and design • Ease and improve testing process through automated checking • Improve integration of development activities via common methodologies • Improve quality and completeness of documentation • Help standardize the development process • Improve project management • Simply program maintenance • Promote reusability • Improve software portability System Analysis and Design System Analysis

  11. Modeling Tools and Techniques • Functional Decomposition Diagram ( FDD ) • A top-down representation of a function or process • A function diagram only shows what to do not how to do. • FDD is a process of division, from a higher function to appropriate smaller functions. • FDD need to be presented clearly, simply, exactly, and fully . • FDD can be used at several stages of systems development System Analysis and Design System Analysis

  12. Modeling Tools and Techniques Four-level functional decomposition diagram (FDD) of a library system. System Analysis and Design System Analysis

  13. Modeling Tools and Techniques • Unified Modeling Language ( UML ) • UML is a method of visualizing and documenting software systems design • UML uses object-oriented design concepts • UML is independent of any specific programming language • UML used to describe business processes and requirements generally • UML provides various graphical tools System Analysis and Design System Analysis

  14. System Requirements Checklist • System Requirements Checklist • System developers must identify and describe all system requirements • System Requirements are a characteristics or features that must be included in an information system to satisfy business requirements and be acceptable to users System Analysis and Design System Analysis

  15. System Requirements Checklist • Five categories of system requirements • Outputs • Inputs • Processes • Performance • Controls • In the next slides some examples of system requirements System Analysis and Design System Analysis

  16. System Requirements Checklist • Outputs • The Web site must report online volume statistics every four hours, and hourly during peak periods • Inputs • The department head must enter overtime hours on a separate screen System Analysis and Design System Analysis

  17. System Requirements Checklist • Processes • The student records system must calculate the GPA at the end of each semester • Performance • Response time must not exceed four seconds • Controls • An employee record must be added, changed, or deleted only by a member of the human resources department System Analysis and Design System Analysis

  18. Future Growth, Costs, and Benefits • In addition to the system requirements, system analyst must consider • Scalability • Total Cost of Ownership System Analysis and Design System Analysis

  19. Future Growth, Costs, and Benefits • Scalability • System’s ability to handle increased business volume and transactions in the future • A scalable system offers a better return on the initial investment • To evaluate, you need information about projected future volume for all outputs, inputs, and processes System Analysis and Design System Analysis

  20. Future Growth, Costs, and Benefits • Total cost of ownership (TCO) • A number that is used in assessing costs, which includes ongoing support and maintenance costs, as well as acquisition costs. • TCO especially important if the development team is evaluating several alternatives • One problem is that cost estimates tend to understate indirect costs • Systems analysts should try to identify indirect costs and include them in TCO estimates System Analysis and Design System Analysis

  21. Sequence Summary • The systems analysis phase includes three activities: requirements modeling, data and process modeling, and consideration of development strategies • The main objective is to understand the proposed project and build a solid foundation for the systems design phase • You identify the business-related requirements for the new information system, including outputs, inputs, processes, performance, and controls • You consider scalability to ensure that the system can support future growth and expansion • You also estimate total cost of ownership (TCO) to identify all costs, including indirect costs • UML is a method of visualizing and documenting software systems design • CASE tools are automated software tool used by systems analysts to develop information systems System Analysis and Design System Analysis

  22. Sequence Summary • In this Sequence we have • Described the systems analysis phase including three activities: requirements modeling, data and process modeling, and consideration of development strategies • Explained the main analysis objective that is to understand the proposed project and build a solid foundation for the systems design phase • identified the business-related requirements for the new information system, including outputs, inputs, processes, performance, and controls • Identified the fact-finding process includes interviewing, document review, observation, questionnaires, sampling, and research • Described the Unified Modeling Language (UML) • Described Functional Decomposition Diagram ( FDD ) • Explained why analysts using models • Describe CASE tools, objectives, and types System Analysis and Design System Analysis

  23. 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 System Analysis and Design System Analysis