Chap 1_Overview of Information System Development Environment.pdf

IT 352 Information Systems Analysis and Design By: Haifa Alhasson 2020 Brief List of Topics Overview of Information System development environment Managing the Information Systems Project Identifying and Selecting Sys...

IT 352 Information Systems Analysis and Design By: Haifa Alhasson 2020 Brief List of Topics Overview of Information System development environment Managing the Information Systems Project Identifying and Selecting Systems Development Projects Initiating and Planning Systems Development Projects Determine the system requirements Structuring System Process Requirements Designing information systems System Implementation Maintaining Information Systems Reference Modern Systems Analysis and Design 6th/8th Edition By Hoffer, George & Valacich, 2012/2017  Chapter- 1 The Systems Development Environment  Learning Objectives  Define information systems analysis and design.  Describe the information Systems Development Life Cycle (SDLC).  Explain Rapid Application Development (RAD), prototyping, Computer Aided Software Engineering (CASE), and Service- Oriented Architecture (SOA).  Describe agile methodologies and extreme programming.  Explain Object Oriented Analysis and Design and the Rational Unified Process (RUP).  Introduction  Information Systems Analysis and Design  Complex organizational process  Used to develop and maintain computer- based information systems  Used by a team of business and systems professionals 6 Introduction (Cont.) FIGURE 1-1 An organizational approach to systems analysis and design is driven by methodologies, techniques, and tools 7 Technique: are particular process that you as analyst will follow to help ensure that your work is well through out and clear to others on your project team. Methodologies: are comprehensive multiple step approaches to system development that guide your work and influence the quality of your final product. Tools: are typically computer programs that make it easy to use and benefit from the technique and faithfully follow the guideline of the overall development methodology. 8  A Modern Approach to Systems Analysis and Design (Cont.) Application Software Computer software designed to support organizational functions or processes Systems Analyst Organizational role most responsible for analysis and design of information systems 12  Developing Information Systems  System Development Methodology is a standard process followed in an organization to conduct all the steps necessary to analyze, design, implement, and maintain information systems. 13  Systems Development Life Cycle (SDLC) Traditional methodology used to develop, maintain, and replace information systems. Phases in SDLC:  Planning  Analysis  Design  Implementation  Maintenance 14  Standard and Evolutionary Views of SDLC FIGURE 1-2 FIGURE 1-3 Evolutionary model The systems development life cycle 15 Systems Development Life Cycle (SDLC) (Cont.) Planning – An organization’s total information system needs are identified, analyzed, prioritized, and arranged Analysis – System requirements are studied and structured 16 Systems Development Life Cycle (SDLC) (Cont.) Design – a description of the recommended solution is converted into logical and then physical system specifications Logical design – all functional features of the system chosen for development in analysis are described independently of any computer platform 17 Systems Development Life Cycle (SDLC) (Cont.) Physical Design – the logical specifications or condition of the system from logical design are transformed into the technology-specific details from which all programming and system construction can be accomplished or able. 18 Systems Development Life Cycle (SDLC) (Cont.) Implementation – the information system is coded, tested, installed and supported in the organization Maintenance – an information system is systematically repaired and improved 19 20 The Heart of the Systems Development Process FIGURE 1-7 FIGURE 1-8 The analysis–design–code–test loop The heart of systems development Current practice combines analysis, design, and implementation into a single iterative and parallel process of activities.  Traditional Waterfall SDLC One phase begins when another completes, with little backtracking and looping. FIGURE 1-9 A traditional waterfall SDLC 22  Problems with Waterfall Approach  System requirements “locked in” after being determined (can't change)  Limited user involvement (only in requirements phase)  Too much focus on milestone or target deadlines of SDLC phases to the detriment or damage of sound development practices 23 Different Approaches to Improving Development  CASE Tools  Rapid Application Development (RAD)  Agile Methodologies  eXtreme Programming 24 Computer-Aided Software Engineering (CASE) Tools  Diagramming tools enable or allow graphical representation.  Computer displays and report generators help prototype how systems “look and feel”. 25 Computer-Aided Software Engineering (CASE) Tools (Cont.)  Analysis tools automatically check for consistency in diagrams, forms, and reports.  A central repository or storehouse provides integrated storage of diagrams, reports, and project management specifications. 26 Computer-Aided Software Engineering (CASE) Tools (Cont.)  Documentation generators standardize technical and user documentation.  Code generators enable automatic generation of programs and database code directly from design documents, diagrams, forms, and reports. 27 CASE Tools (Cont.) FIGURE 1-10 A class diagram from IBM’s Rational Rose (Source: IBM) 28 CASE Tools (Cont.) 29 Rapid Application Development (RAD)  RAD is an approach to developing information systems that promises better and cheaper systems and more rapid development by having system developers and end user work together jointly in real time develop system.  Methodology to radically decrease design and implementation time  Involves: extensive user involvement, prototyping, Joint Application Design(JAD)sessions, integrated CASE tools, and code generators 30 Rapid Application Development (RAD) (Cont.) FIGURE 1-11 RAD life cycle 31  Service-Oriented Architecture (SOA)  An approach to systems development based on building complete systems through assembling software components, each of which model generic business functions 32  Service-Oriented Architecture (SOA) (Cont.) FIGURE 1-12 Illustration of a service, a credit check, used by applications and other services 33  Agile Methodologies Motivated by recognition of software development as fluid or solution, unpredictable, and dynamic Three key principles  Adaptive rather than predictive  Emphasize people rather than roles  Self-adaptive processes 34 The Agile Methodologies group argues that software development methodologies adapted from engineering generally do not fit with real- world software development. 35  When to use Agile Methodologies If your project involves:  Unpredictable or dynamic requirements  Responsible and motivated developers  Customerswho understand the process and will get involved 36 37  eXtreme Programming  Short, incremental development cycles  Automated tests  Two-person programming teams 38  eXtreme Programming (Cont.)  Coding and testing operate together  Advantages:  Communication between developers  High level of productivity  High-quality code 39 Object-Oriented Analysis and Design (OOAD)  Based on objects rather than data or processes  Object: a structure encapsulating attributes and behaviors of a real-world entity 40 Object-Oriented Analysis and Design (OOAD) (Cont.)  Object class: a logical grouping of objects sharing the same attributes and behaviors  Inheritance: hierarchical arrangement of classes enable subclasses to inherit properties of super classes 41  Rational Unified Process (RUP)  An object-oriented systems development methodology  RUP establishes four phase of development: inception, elaboration, construction, and transition.  Inception phase analyst define the scope determine the feasibility of the project understand the user requirements and prepare a software development plan.  In elaboration analyst detail user requirements and develop a base line architecture.  In construction phase the software actually coded, tested and documented.  In transition phase the system is deployed and the user are trained and supported.  Each phase is organized into a number of separate iterations. 42 FIGURE 1-13 Phases of OOSAD-based development 43 Our Approach to Systems Development  The SDLC is an organizing and guiding principle in this book.  We may construct artificial boundaries or artificially separate activities and processes for learning purposes.  Our aim is to help you and you understand all the pieces and how to assemble them. 44  Summary In this chapter you learned how to:  Define information systems analysis and design.  Describe the information Systems Development Life Cycle (SDLC).  Explain Rapid Application Development (RAD), prototyping, Computer Aided Software Engineering (CASE), and Service- Oriented Architecture (SOA).  Describe agile methodologies and eXtreme programming.  Explain Object Oriented Analysis and Design and the Rational Unified Process (RUP). 45