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Introduction to Systems Analysis and Design. Chapter 1. Chapter Objectives . Discuss the impact of information technology on business Define an information system and explain its components Use profiles and models to understand business functions and operations
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Chapter Objectives • Discuss the impact of information technology on business • Define an information system and explain its components • Use profiles and models to understand business functions and operations • Understand the impact of the Internet on business • Identify various types of information systems and explain who uses them
Chapter Objectives • Explain systems development tools, including modeling, prototyping, and CASE tools • Distinguish between structured analysis and object-oriented methodology • Describe the systems development life cycle • Discuss the role of the information technology department and the systems analysts who work there
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 Figure 1-1
The Impact of Information Technology • 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
The Impact of Information Technology • The Future of IT • Responsible for half of all productivity growth and a third of all economic growth between 1995-1999 Figure 1-3
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
The Impact of Information Technology Figure 1-4
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
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 • Information systems have five key components: hardware, software, data, processes, and people Figure 1-6
Information System Components Figure 1-9
Information System Components • Hardware • Everything in the physical layer of the information system • Moore’s Law accurately predicted that computer processing power would double every 18 to 24 months
Information System Components • Software • System software • Network operating system • Application software • Enterprise applications • Horizontal system • Vertical system • Legacy systems
Information System Components • Data • The raw material that an information system transforms into useful information Figure 1-11
Information System Components • Processes • Describe 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
Understanding The Business • Business Profile • Overview of a company • Business Models • Graphical representation of one or more business processes Figure 1-12
Understanding The Business • New Kinds of Companies • Companies are classified based on their main activities: • Production-oriented • Service-oriented • Brick-and-mortar • Dot-com (.com) Figure 1-14
Impact of the Internet • E-Commerce (I-Commerce) • Internet-based commerce • B2C (Business-to-Consumer) • Consumers can go online to purchase a variety of products and services • B2B (Business-to-Business) • Enables smaller suppliers to contact large customers and allows purchasers to obtain instant information about market prices and availability
Impact of the Internet • B2B (Business-to-Business) • EDI • Computer-to-computer transfer of data between companies • Web-Based System Development • Internet-based systems development is rapidly changing • WebSphere • .NET
How Business Uses InformationSystems • In the 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
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
How Business Uses Information Systems • Enterprise computing systems • Information systems that support company-wide operations and data management Figure 1-17
How Business Uses Information Systems • Transaction processing systems • Process data generated by day-to-day business operations Figure 1-18
How Business Uses Information Systems • Business support systems • Provide job-related information to users at all levels of a company • Management information systems (MIS) • What-if Figure 1-19
How Business Uses Information Systems • Knowledge management systems • Simulate human reasoning Figure 1-20
How Business Uses Information Systems • User productivity systems • Technology that improves productivity • Word processing is an example • Information systems integration • Most large companies require systems that combine transaction processing, business support, knowledge management, and user productivity features
Information System Users and Their Needs Figure 1-21
Information System Users and Their Needs • Top managers • Middle Managers and Knowledge Workers • Supervisors and Team Leaders • Operational Employees
Systems Development Tools and Techniques • Systems analysts must know how to use a variety of techniques such as modeling, prototyping, and computer-aided systems engineering tools to plan, design, and implement information systems • Systems analysts work with these tools in a team environment
Systems Development Tools and Techniques • Modeling • A systems analyst can describe and simplify an information system by using a set of business, data, object, and process models.
Systems Development Tools and Techniques • Prototyping • Early working version of an information system • Speeds up the development process significantly • Can be an extremely valuable tool
Systems Development Tools and Techniques • Computer-Aided Systems Engineering (CASE) Tools • CASE uses powerful software to help systems analysts develop and maintain information systems Figure 1-22
Systems Development Methods • Structured Analysis • traditional systems development technique • Uses the systems development life cycle to plan, analyze, design, implement, and support an information system Figure 1-25
Systems Development Methods • Object-oriented (O-O) analysis • combines data and the processes that act on the data into things called objects • Systems analysts use O-O to model real-world business processes and operations
Systems Development Methods • Object-oriented (O-O) analysis Figure 1-26
Systems Development Methods • Joint Application Development and Rapid Application Development • JAD – Team based fact finding • RAD – compressed version of the entire process
Systems Development Methods • Other development methodologies • In addition to structured analysis and O-O methodologies, you might encounter other systems development techniques • Microsoft Solutions Framework (MSF) documents the experience of its own IT teams
The Systems Development Life Cycle • SDLC used to plan and manage the systems development process. • It includes the following steps: • Systems planning • Systems analysis • Systems design • Systems implementation • Systems operation and support
The Systems Development Life Cycle Figures 1-28 & 1-29
The Systems Development Life Cycle • Systems planning • Purpose is to identify the nature and scope of the business opportunity or problem • Systems request – begins the process & describes problems or desired changes • Systems planning includes preliminary investigation whose key part is a feasibility study
The Systems Development Life Cycle • Systems Analysis • Purpose is to build a logical model of the new system • First step is requirements modeling, where you investigate business processes and document what the new system must do • End product is the System requirements document
The Systems Development Life Cycle • Systems Design • Purpose is to create a blueprint that will satisfy all documented requirements • Identify all outputs, inputs, and processes • Avoid misunderstanding through manager and user involvement • End product is system design specification
The Systems Development Life Cycle • Systems Implementation • New system is constructed • Write, test, & document programs • File conversion occurs • Users, managers, IT staff trained to operate and support the system • System evaluation performed
The Systems Development Life Cycle • Systems Operation and Support • IT staff maintains and enhances the system • Maintenance changes correct errors and adapt to changes in the environment • Enhancements provide new features and benefits • Well-designed system will be reliable, maintainable, and scalable
The Systems Development Life Cycle • Systems Development Guidelines • Stick to a plan • Involve users • Identify milestones • Establish checkpoints • Be flexible • Provide accurate and reliable cost and benefit information
Information Technology Department • The information technology (IT) department develops and maintains a company’s information systems Figure 1-30
Information Technology Department • Application Development • Team may include users, managers and IT Staff members • Systems Support • Provides hardware and software support • User Support • Provides users with technical information, training, and productivity support
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 • Design and construction of web pages and presence. Important for e-commerce
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
The Systems Analyst Position • Responsibilities • Required Skills and Background Figure 1-31