Introduction to Systems Analysis and Design Chapter 1 Introduction to Systems Analysis and Design

Chapter Objectives Discuss information technology Define an information system and explain its components Use profiles and models to understand business functions and operations Identify various types of information systems and explain who uses them 3

Chapter Objectives Explain systems development tools, including modeling, and prototyping Describe the systems development life cycle Discuss the role of the information technology department and the systems analysts who work there 3

IT, Information Technolgy Information system are used to increase productivity, deliver quality products and services, maintain customer loyalty, and make sound decisions. Figure 1-1 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

Vocabulary Business rule – The collection of practices that describe how an enterprise really functions. Policy – written business strategy that may not be a practice Procedures – tasks performed to achieve specific results Practice – observable actions carried out

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 Information systems have five key components: hardware, software, data, processes, and people Figure 1-6 12

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 13

Information System Components Software System software Network operating system Application software Enterprise applications Horizontal system Vertical system Legacy systems 14

Information System Components Data The raw material that an information system transforms into useful information Figure 1-11 15

Information System Components What is a Process? 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 16

Understanding The Business Business Profile Overview of a company Business Models Graphical representation of one or more business processes Figure 1-12 9

How Business Uses Information Systems Enterprise computing systems Information systems that support company-wide operations and data management Figure 1-17 21

How Business Uses Information Systems Transaction processing systems Process data generated by day-to-day business operations Figure 1-18 22

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 23

How Business Uses Information Systems Knowledge management systems Simulate human reasoning Figure 1-20 24

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 25

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

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

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

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 30

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 32

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 33

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 34

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 35

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 36

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 37

Information Technology Department The information technology (IT) department develops and maintains a company’s information systems Figure 1-30 41

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 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 Design and construction of web pages and presence. Important for e-commerce 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

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. 49

Chapter Summary Based on their function and features, information systems are identified Organization structure usually includes levels Systems analyst use modeling, prototyping, and CASE tools Various development methodologies exist, including structured analysis and object-oriented analysis 49

Chapter Summary An IT department develops, maintains and operates a company’s information systems Systems analysts need a combination of technical and business knowledge, analytical ability, and communication Chapter 1 Complete 49