Systems Analysis & Design 7th Edition Chapter 1

Chapter Objectives Discuss the impact of information technology on business strategy and success Define an information system and describe its components Explain how profiles and models can represent business functions and operations Explain how the Internet has affected business strategies and relationships Identify various types of information systems and explain who uses them 3

Chapter Objectives Explain modeling, prototyping, and CASE tools Distinguish between structured analysis and object-oriented analysis Compare the systems development life cycle waterfall model to adaptive models Discuss the role of the information technology department and the systems analysts who work there 3

Introduction Companies use information as a weapon in the battle to increase productivity, deliver quality products and services, maintain customer loyalty, and make sound decisions Information technology can mean the difference between success and failure 4

The Impact of Information Technology Combination of hardware and software products and services that companies use to manage, access, communicate, and share information A vital asset that must be used effectively, updated constantly, and safeguarded carefully 4

The Impact of Information Technology The Future of IT Accounts for almost 30 percent of America’s economic growth, and the wage gaps between IT workers and all other workers will continue to widen Global online population skyrocketed between 2000 and 2005 4

The Impact of Information Technology The Role of Systems Analysis and Design Systems Analysis and Design Step-by-step process for developing high-quality information systems Systems Analyst Plan, develop, and maintain information systems 4

The Impact of Information Technology Who develops Information Systems? In-house applications Software packages Internet-based application services Outsourcing Custom solutions Enterprise-wide software strategies How versus What 4

Information System Components A system is a set of related components that produces specific results A mission-critical system is one that is vital to a company’s operations Data consists of basic facts that are the system’s raw material 12

Information System Components Hardware Moore’s Law Software System software Application software Enterprise applications Horizontal system 13

Information System Components Software Vertical system Legacy systems Data Tables Linking

Information System Components Processes Define the tasks and business functions that users, managers, and IT staff members perform to achieve specific results People Users, or end users, are the people who interact with an information system, both inside and outside the company 16

Understanding The Business Business Process Modeling Business Profile Business Models Business model Business process Business process reengineering (BPR) 9

Understanding The Business New Kinds of Companies Production-oriented Service-oriented Internet-dependent Dot-com (.com) Brick-and-mortar 18

Impact of the Internet E-Commerce or I-Commerce B2C (Business-to-Consumer) B2B (Business-to-Business) EDI Extensible markup language (XML) Supplier relationship management (SRM) 18

Impact of the Internet Web-Based System Development WebSphere .NET Web services 18

How Business Uses Information Systems In past, IT managers divided systems into categories based on the user group the system served Office systems Operational systems Decision support systems Executive information systems 19

How Business Uses Information Systems Today, it makes more sense to identify a system by its functions, rather than by users Enterprise computing systems Transaction processing systems Business support systems Knowledge management systems User productivity systems 20

How Business Uses Information Systems Enterprise computing systems Support company-wide operations and data management requirements Transaction processing systems Efficient because they process a set of transaction-related commands as a group rather than individually 21

How Business Uses Information Systems Business support systems Provide job-related information to users at all levels of a company Management information systems (MIS) Radio frequency identification (RFID) What-if 23

How Business Uses Information Systems Knowledge management systems Called expert systems Simulate human reasoning by combining a knowledge base and inference rules Many use fuzzy logic 24

How Business Uses Information Systems User productivity systems Technology that improves productivity Groupware Information systems integration Most large companies require systems that combine transaction processing, business support, knowledge management, and user productivity features 25

Information System Users and Their Needs 27

Information System Users and Their Needs Top managers Middle Managers and Knowledge Workers Supervisors and Team Leaders Operational Employees 27

Systems Development Tools and Techniques Modeling Models are used to describe and simplify an IS Prototyping Test system concepts Computer-Aided Systems Engineering CASE tools

Systems Development Tools and Techniques Modeling Business/Requirements model: Information the systems must provide (Ch 3) Data model : how data is represented and accessed (ch. 4) Object model: describe objects which combine data and processes Network model: the design and protocols of networks Process model: outlines the logical processes and their interrelationships (Ch 4)

Systems Development Tools and Techniques Prototyping Prototype Speeds up the development process significantly Important decisions might be made too early, before business or IT issues are thoroughly understood Can be an extremely valuable tool

Systems Development Tools and Techniques Computer-Aided Systems Engineering (CASE) Tools Also called computer-aided software engineering

Systems Development Methods Alternatives: Systems development life cycle (SDLC) Traditional approach Object-oriented analysis (O-O) Newer approach Mixed method

Systems Development Methods Structured Analysis Systems development life cycle (SDLC) Uses a series of phases: Plan, Analyze, Design, Implement, Support Predictive approach Process-centered technique Uses a set of process models to describe a system graphically Process models – identify data flowing into a process, rules for transformation, and output flows

Systems Development Methods Sample Process model

Systems Development Methods Object-oriented Analysis O-O analysis combines data & processes into objects Object is a member of a class Objects possess properties Methods change an object’s properties A message requests specific behavior or information from another object

Systems Development Methods Object-oriented Analysis The PERSON class includes INSTRUCTOR and STUDENT objects, which have their own properties and inherited properties.

Planning and Modeling a Systems Development Project In addition to selecting a development method, system developers also must create a plan or model for the many tasks that will be required Typically, the development team will use project management tools to help achieve the end result

Planning and Modeling a Systems Development Project The SDLC Waterfall Model The phases and deliverables of the SDLC are shown in the waterfall model.

Planning and Modeling a Systems Development Project The SDLC Waterfall Model Disadvantage in the built-in structure of the SDLC, because the waterfall model does not emphasize interactivity among the phases This criticism can be valid if the SDLC phases are followed too rigidly However, adjacent phases usually interact

Planning and Modeling a Systems Development Project Adaptive approach – spiral development model builds on a series of iterations.

Planning and Modeling a Systems Development Project Adaptive Methods and Models Attempt to develop a system incrementally, by building a series of prototypes and constantly adjusting them to user requirements Extreme Programming (XP) Analysts should recognize that these approaches have advantages and disadvantages 37

Planning and Modeling a Systems Development Project The SDLC Waterfall Model Usually includes five steps Systems planning Systems analysis Systems design Systems implementation Systems operation, support, and security 30

Planning and Modeling a Systems Development Project Systems planning Systems request Purpose of this phase is to perform a preliminary investigation whose key part is a feasibility study Systems Analysis First step is requirements modeling End product is the System requirements document 32

Planning and Modeling a Systems Development Project Systems Design Identify all outputs, inputs, and processes End product is system design specification Systems Implementation New system is constructed Users, managers, IT staff trained to operate and support the system System evaluation performed 34

Planning and Modeling a Systems Development Project Systems Operation, Support, and Security A well-designed system must be secure, reliable, maintainable, and scalable After several years of operation, systems need extensive changes SDLC ends with system replacement 36

Planning and Modeling a Systems Development Project Joint Application Development and Rapid Application Development Methods and Models Joint application development (JAD) Rapid application development (RAD) Other Development Methods and Models Rational Unified Process (RUP®) Microsoft Solutions Framework (MSF)

Planning and Modeling a Systems Development Project The Importance of Project Management Regardless of the development strategy, people, tasks, timetables, and expenses must be managed effectively Complex projects can involve dozens of people, hundreds of tasks, and many thousands of dollars

Systems Development Guidelines Stick to a plan Involve the users throughout the development process Listening is very important Use project management tools to identify tasks and milestones Remain flexible Develop accurate cost and benefit information

Information Technology Department The information technology (IT) department develops and maintains a company’s information systems The IT group provides technical support 41

Information Technology Department Application Development Team may include users, managers and IT Staff members Systems Support and Security Deployment team User Support Help desk or information center (IC) 41

Information Technology Department Database Administration Database design, management, security, backup, and user access Network Administration Includes hardware and software maintenance, support, and security Web Support Webmasters 41

Information Technology Department Quality Assurance (QA) Reviews and tests all applications and systems changes to verify specifications and software quality standards Is a separate unit that reports directly to IT management 41

The Systems Analyst Position A systems analyst investigates, analyzes, designs, develops, installs, evaluates, and maintains a company’s information systems On large projects, the analyst works as a member of an IT department team Smaller companies often use consultants to perform the work 42

The Systems Analyst Position Responsibilities Translate business requirements into practical IT projects to meet needs Required Skills and Background Solid communication skills and analytic ability 42

The Systems Analyst Position Certification Career Opportunities Job titles Company organization Company size Corporate culture Salary, location, and future growth 42

Chapter Summary IT is a combination of hardware, software, and telecommunications systems that support business The essential components of an information system are hardware, software, data, processes, and people Companies are production oriented, service oriented, or a combination of the two Organization structure usually includes levels 49

Chapter Summary Systems analyst use modeling, prototyping, and CASE tools Various development methodologies exist Regardless of the development model, it is important to use project management tools necessary to manage people, tasks, timetables, and expenses An IT department develops, maintains and operates a company’s information systems 49

Chapter Summary Systems analysts need a combination of technical and business knowledge, analytical ability, and communication Chapter 1 complete 49