IST243-Chapter 1.pdf

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 Chapter 1 Copyright © 2014 Pearson Education, Inc....

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 Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 1 Introduction (Cont.) FIGURE 1-1 An organizational approach to systems analysis and design is driven by methodologies, techniques, and tools Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 2 Introduction (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 Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 3 A Modern Approach to Systems Analysis and Design 1950s: focus on efficient automation of existing processes 1960s: advent of procedural third generation languages (3GL) faster and more reliable computers 1970s: system development becomes more like an engineering discipline Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 4 A Modern Approach to Systems Analysis and Design (Cont.) 1980s: major breakthrough with 4GL, CASE tools, object-oriented methods 1990s: focus on system integration, GUI applications, client/server platforms, Internet The new century: Web application development, wireless PDAs and smart phones, component-based applications, application service providers (ASP) Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 5 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. Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 6 Systems Development Life Cycle (SDLC) Traditional methodology used to develop, maintain, and replace information systems Phases in SDLC:  Planning  Analysis  Design  Implementation  Maintenance Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 7 Standard and Evolutionary Views of SDLC FIGURE 1-3 Evolutionary model FIGURE 1-2 Systems development life cycle Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 8 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 Design – a description of the recommended solution is converted into logical and then physical system specifications Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 9 Systems Development Life Cycle (SDLC) (Cont.) Logical design – all functional features of the system chosen for development in analysis are described independently of any computer platform Physical design – the logical specifications of the system from logical design are transformed into the technology-specific details from which all programming and system construction can be accomplished Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 10 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 Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 11 Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 12 The Heart of the Systems Development Process FIGURE 1-8 FIGURE 1-9 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. Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall Traditional Waterfall SDLC One phase begins when another completes, with little backtracking and looping. FIGURE 1-10 Traditional waterfall SDLC Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 14 Problems with Waterfall Approach Feedback ignored, milestones lock in design specs even when conditions change Limited user involvement (only in requirements phase) Too much focus on milestone deadlines of SDLC phases to the detriment of sound development practices Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 15 Different Approaches to Improving Development CASE Tools Rapid Application Development (RAD) Agile Methodologies eXtreme Programming Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 16 Computer-Aided Software Engineering (CASE) Tools Diagramming tools enable graphical representation. Computer displays and report generators help prototype how systems “look and feel”. IBM’s Rational products are the best known CASE tools. Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 17 Computer-Aided Software Engineering (CASE) Tools (Cont.) Analysis tools automatically check for consistency in diagrams, forms, and reports. A central repository provides integrated storage of diagrams, reports, and project management specifications. Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 18 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. Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 19 CASE Tools (Cont.) FIGURE 1-11 Screen shot of ArgoUML, an open source CASE tool (Source: http://argouml.tigris.org/) Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 20 CASE Tools (Cont.) Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 21  Rapid Application Development (RAD) Decreases design and implementation time Involves: extensive user involvement, prototyping, integrated CASE tools, code generators More focus on user interface and system function, less on detailed business analysis and system performance Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 22  Rapid Application Development (RAD) (Cont.) FIGURE 1-12 RAD life cycle Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 23  Agile Methodologies Motivated by recognition of software development as fluid, unpredictable, and dynamic Three key principles  Adaptive rather than predictive  Emphasize people rather than roles  Self-adaptive processes Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 24 When to use Agile Methodologies If your project involves:  Unpredictable or dynamic requirements  Responsible and motivated developers  Customers who understand the process and will get involved Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 25 eXtreme Programming Short, incremental development cycles Automated tests Two-person programming teams Coding, testing, listening, designing Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 26 eXtreme Programming (Cont.) Coding and testing operate together Advantages:  Communication between developers  High level of productivity  High-quality code Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 27 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 Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 28 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 superclasses Chapter 1 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 29 Managing the Information Systems Project Project A planned undertaking of related activities to reach an objective that has a beginning and an end Project management A controlled process of initiating, planning, executing, and closing down a project Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 30 Managing the Information Systems Project (cont.) Project manager A systems analyst with a diverse set of skills— management, leadership, technical, conflict management, and customer relationship—who is responsible for initiating, planning, executing, and closing down a project Deliverable  The end product of an SDLC phase Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 31 Deciding on Systems Projects System Service Request (SSR) A standard form for requesting or proposing systems development work within an organization Feasibility study A study that determines whether a requested system makes economic and operational sense for an organization Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 32  Project Management Activities FIGURE 3-4 A project manager juggles numerous activities Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 33 Phases of Project Management Process Phase 1: Initiation Phase 2: Planning Phase 3: Execution Phase 4: Closedown Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 34 PM Phase 1: Project Initiation Assess size, scope and complexity, and establish procedures. Establish:  Initiationteam  Relationship with customer  Project initiation plan  Management procedures  Project management environment and workbook  Project charter Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 35 Project Charter A short document prepared for the customer describing project deliverables and outlining the work required to complete the project Elements:  Title and authorization date  Project manager name and contact information  Customer name and contact information  Project start and completion dates  Key stakeholders, roles, responsibilities  Project objectives and description  Key assumptions  Signatures of stakeholders Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 36  PM Phase 2: Project Planning Define clear, discrete activities and the work needed to complete each activity. Tasks include: 1. Describing Project Scope, 6. Determining Project Alternatives, and Feasibility Standards and Procedures 2. Dividing the Project into 7. Identifying and Assessing Manageable Tasks Risk 3. Estimating Resources and 8. Creating a Preliminary Creating a Resource Plan Budget 4. Developing a Preliminary 9. Developing a Project Schedule Scope Statement 5. Developing a 10. Setting a Baseline Project Communication Plan Plan Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 37 Developing a Communication Plan Who are stakeholders? What information does each stakeholder need? When should information be produced? What are sources of information? Who will collect, store and validate info? Who will organize and document info? Who is the contact person for each stakeholder? What is the appropriate/best format for info? What communication medium should be used? Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 38 Setting a Baseline Project Plan A Baseline Project Plan provides an estimate of the project’s tasks and resource requirements and is used to guide the next project phase—execution. As new information is acquired during project execution, the baseline plan will continue to be updated. Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 39 PM Phase 3: Project Execution Plans created in prior phases are put into action. Actions  Execute baseline project plan.  Monitor progress against baseline plan.  Manage changes in baseline plan.  Maintain project workbook.  Communicate project status. Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 40 PM Phase 4: Project Closedown Bring the project to an end. Actions  Close down the project.  Conduct post-project reviews.  Close the customer contract. Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 41 Representing and Scheduling Project Plans Gantt Charts Network Diagrams PERT Calculations Critical Path Scheduling Project Management Software Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 42 Gantt Charts vs. Network Diagrams Gantt charts  Show task durations.  Show time overlap.  Show slack time in duration. Network diagrams  Show task dependencies.  Do not show time overlap, but show parallelism.  Show slack time in boxes. Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 43 Gantt Charts vs. Network Diagrams (Cont.) Figure 3-19 Graphical diagrams that depict project plans (a) A Gantt chart (b) A network diagram (Source: Microsoft Corporation.) Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 44 Gantt Charts vs. Network Diagrams (Cont.) Figure 3-21 A network diagram showing activities (represented by circles) and sequence of those activities (represented by arrows) Chapter 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 45  References  Jeffrey A. Hoffer, Joey F. George, Joseph S. Valacich, Modern System Analysis and Design, 6th Edition, Pearson International Edition, 2014. ISBN 978-81-317-6141-0 Chapter 1 & 3 Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 46