Computers Are Your Future Tenth Edition Chapter 13: Systems Analysis & Design Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall1

2 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States of America. Copyright © 2009 Pearson Education, Inc. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall

What You Will Learn Explain what systems analysts do. Understand the concept of a system and its life cycle. Discuss why the systems development life cycle (SDLC) is so widely used. List the five phases of the SDLC. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall3

What You Will Learn Describe the classic mistakes of failed information systems development projects and how systems analysts can avoid them. Discuss the activities in each of the five phases of the SDLC. Name the deliverables of each of the five phases of the SDLC. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall4

Systems Analysis & Design Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall5

System Analysts: Communication Counts Systems analysis Involves information systems planning, development, and maintenance Performed in an organized manner System analysts determine the information system requirements of an organization based on input from users and management. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall6

System Analysts: Communication Counts Systems analysts must possess excellent communication and listening skills to help develop an effective information system. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall7

The Systems Development Life Cycle Development of information systems Used to be chaotic Often resulted in inadequate results Systems development life cycle (SDLC) Means to organize development Consists of five phases Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall8

The Systems Development Life Cycle Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall9

The Systems Development Life Cycle Systems Made up of a grouping of parts that work together to achieve an objective Have life cycles that start with their creation, go through growth and changes, and end with obsolescence. Artificial system: Developed by people rather than by nature Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall10

The Systems Development Life Cycle The system development life cycle’s philosophy: You cannot proceed to the next phase before the previous one is completed. Each phase must provide a deliverable that often serves as the input for the next phase. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall11

The Systems Development Life Cycle Systems development wisdom: Involve users. Use a problem-solving methodology to provide effective results. Use strong project management skills. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall12

The Systems Development Life Cycle Systems development wisdom (continued): Document all important facts about a project. Use checkpoints to keep work on target. Anticipate future growth and change while designing the system. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall13

The Systems Development Life Cycle An accepted concept in the systems development life cycle is the waterfall model, which enables analysts to revisit a prior phase through corrective pathways when problems arise. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall14

Phase 1: Planning the System Phase 1 includes the following tasks: Recognizing the needs of the system Defining the problem Examining alternative solutions Developing a plan Determining feasibility Preparing the project proposal Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall15

Phase 1: Planning the System Recognition of the need for a new or modified system may come from acknowledging deficiencies. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall16

Phase 1: Planning the System Defining the problem cannot occur until it is understood Problem: the underlying cause of a symptom Symptom: the unacceptable result of a problem Once the problem is defined: Use requirements analysis to identify the system requirements based on user needs Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall17

Phase 1: Planning the System After system requirements are defined: Evaluate potential solutions Create a project plan Cites the goals of the system Lists the steps or activities to successful completion of the project Specifies order of completion Estimates time frames Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall18

Phase 1: Planning the System Gantt chart Type of bar chart Used to provide a graphical summary of the milestone tasks and their due dates. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall19

Phase 1: Planning the System Feasibility studies Technical feasibility: Can be completed with existing technology Operational feasibility: Can be accomplished with the available resources Economic feasibility: Can be done with the available fiscal resources Often involves a cost-benefit analysis Seeks a return on investment (ROI) Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall20

Phase 1: Planning the System Project proposal Phase 1 deliverable A written report Documents details of the system problem and its resolution Concludes with a recommendation. End of Phase 1 Basis for management decision to proceed Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall21

Phase 2: Analyzing & Documenting the Existing System Determine what the new system will do Two parts: Analyzing the current system Determining the requirements of the new system Deliverable: List of requirements for the new system Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall22

Phase 3: Designing the System Determine how the new system information will work List and document specifications using Graphic tools Project dictionaries Data dictionaries Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall23

Phase 3: Designing the System Design tools used during this phase: Entity-relationship diagram (ERD) Data flow diagram (DFD) Rapid application development (RAD) Computer-aided software engineering (CASE) Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall24

Phase 3: Designing the System Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall25 Entity relationship diagram

Phase 3: Designing the System Rapid Application Development (RAD) Also known as prototyping Create small mock-up of system early in the process Provide enough functionality to get feedback from users Advantage: Users have something concrete to review Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall26

Phase 3: Designing the System Computer-Aided Software Engineering (CASE) For complex systems Automates documenting entity relationships and data flow CASE tools include project management features, data dictionaries, documentation support, and graphical output support, and some generate prototype code Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall27

Phase 3: Designing the System Teams create support material: Project dictionary: defines terminology Data dictionary: identifies the data that will be entered into the system Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall28

Phase 3: Designing the System Phase 3 deliverable: A logical diagram or design that shows how the new system will operate Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall29

Phase 4: Implementing the System Decide whether to create system or outsource development Additional tasks: Developing the software Application and acceptance testing User training System conversion Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall30

Phase 4: Implementing the System Application testing involves assessing the programs separately and as a group. Acceptance testing is performed by the users and ensures that the system works properly. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall31

Phase 4: Implementing the System System conversion methods: Parallel conversion Pilot conversion Phased conversion Direct conversion (crash conversion) The deliverable in Phase 4 is the completed, tested system. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall32

Phase 5: Maintaining the System Review and maintain new system Must meet the needs of the users Must function properly Perform postimplementation system review Evaluates whether the goals of the system are met Serves as Phase 5 deliverable Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall33

What You’ve Learned Systems analysts work with users and management in an effort to develop an information system that meets the organization’s needs. To help develop that information system, the systems analysts use the systems development life cycle (SDLC). Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall34

What You’ve Learned The SDLC is divided into five individual phases, which must be completed in a specific order, one phase at a time. The results of one phase within the SDLC become the starting point for the next phase of the cycle. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall35

What You’ve Learned The five phases of the system development life cycle are (1) planning the system, (2) analyzing and documenting the existing information system, (3) designing the system, (4) implementing the system, and (5) maintaining the system. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall36

What You’ve Learned Deliverables passed on from a previous phase in the SDLC are input to the next phase and include the project proposal, the review of the present information system, a thorough review of the proposed information system, the fully tested finished result, and a system evaluation after its implementation. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall37