System analysis ITM3.pptx
- 1. SYSTEMS ANALYSIS & DESIGN lectures 2017-2018 By: Assistant Lecturer Zhiyan A. younis
- 2. THE IMPACT OF INFORMATION TECHNOLOGY Information technology (IT) refers to the combination of hardware, software, and services that people use to manage, communicate, and share information. Although the huge impact of IT on our society. More than ever, business success depends on information technology. IT is driving a new digital economy, where advances in hardware, software, and connectivity can provide enormous benefits to businesses and individuals. Although economic trends affect IT spending levels, most firms give IT budgets a high priority, in good times or bad(why?). The reason is simple — during periods of growth, companies cannot afford to lag behind the IT curve. Conversely, when the economy slows down, firms often use IT to reduce operating costs and improve efficiency. 236
- 3. The Future If you ask a group of IT professionals to name a company that has been successful for over 100 years, the answer probably would be IBM. As its name suggests, International Business Machines was a major supplier of typewriters and data processing equipment long before the computer era. 337
- 4. UNDERSTAND THE BUSINESS IT professionals must understand a company’s operations to design successful systems. Each business situation is different. Systems analysts use a process called business process modeling to represent company operations and information needs. Business process modeling requires a 1-business profile 2-a series of models that document business processes. 438
- 5. Business Profile A business profile is an overview of a company’s mission, functions, organization, products, services, customers, suppliers, competitors, constraints, and future direction. Although much of this information is readily available, a systems analyst usually needs to do additional research and fact-finding. A business profile is the starting point for the modeling process. 539
- 6. Business Process A business process is a specific set of transactions, events, and results that can be described and documented. A business process model (BPM) graphically displays one or more business processes, such As handling an airline reservation, filling a product order, or updating a customer account. 640
- 7. The example in the below Figure shows a simple model that includes an event, three processes, and a result. Process: Verify Customer Credit Process: Check Customer Status Process: Enter Customer Order Data Event: Receive Sales Order Result: Completed Sales Order 741
- 8. business process modeling notation (BPMN) A rough sketch might be sufficient to document a simple business process. For complex operations, however, analysts apply computer-based modeling tools that use a standard language called business process modeling notation (BPMN). BPMN includes various shapes and symbols to represent events, processes, and workflows, as shown in the example in the next Figure. Modeling tools include multi-purpose graphical applications, such as Microsoft Visio, and computer-aided software engineering programs such as Visible Analyst 842
- 9. This sample uses business process modeling notation (BPMN) to represent events, processes, and workflow. 943
- 10. IMPACT OF THE INTERNET The newest kind of company is the Internet-dependent firm, often described as adot-com (.com) company because its primary business depends on the Internet rather than a traditional business channel. Google, Yahoo!, Amazon, and eBay are examples of pure dot-com companies. 1044
- 11. IMPACT OF THE INTERNET Internet-based commerce is called e-commerce (electronic commerce) or I-commerce (Internet commerce). Internet-based systems involve various hardware and software designs, but a typical model is a series of Web pages that provides a user interface, which communicates with database management software and a Web-based data server. As Internet- based commerce continues to grow, career opportunities will expand significantly for IT Professionals such as Web designers, database developers, and systems analysts. 1145
- 12. SYSTEMS DEVELOPMENT TOOLS In addition to understanding business operations, 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& security information systems. Systems analysts work with these tools in a team environment, where input from users, managers, and IT staff contributes to the system design. 1246
- 13. Modeling Modeling produces a graphical representation of a concept or process that systems developers can analyze, test, and modify. A systems analyst can describe and simplify an information system by using a set of business, data, object, network, and process models. 1347
- 14. Types of modeling • A business model, or requirements model, describes the information that a system must provide. • A data model describes data structures and design. • An object model describes objects, which combine data and processes. • A network model describes the design and protocols of telecommunications links. • A process model describes the logic that programmers use to write code modules. 1448
- 15. Prototyping Prototyping tests system concepts and provides an opportunity to examine input, output, and user interfaces before final decisions are made. 1549
- 16. Computer-Aided Systems Engineering (CASE) Tools Computer-aided systems engineering (CASE), also called computer-aided software engineering, is a technique that uses powerful software, called CASE tools, to help systems analysts develop and maintain information systems. CASE tools provide an overall framework for systems development and support a wide variety of design methodologies, including structured analysis and object-oriented analysis. 1650
- 17. SYSTEMS DEVELOPMENT METHODS the most popular alternatives are 1- structured analysis, which is a traditional method that still is widely used. Structured analysis uses a series of phases, called the systems development life cycle (SDLC), to: • plan(which describes problems or desired changes in an information system or a business process.), • Analyze(to build a logical model of the new system.) • design(to create a physical model that will satisfy all documented requirements for the system.) • implement(the new system is constructed) • support &security(the IT staff maintains, enhances, and protects the system) • 2- object-oriented (O-O) nalysis (combines data and the processes that act on the data into things called objects) 1751
- 18. THE INFORMATION TECHNOLOGY DEPARTMENT The IT department develops and maintains information systems. The structure of the IT department varies among companies 1852
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- 20. THE SYSTEMS ANALYST The systems analyst’s job overlaps business and technical issues. Analysts help translate business requirements into IT projects. When assigned to a systems development team, an analyst might help document business profiles, review business processes, select hardware and software packages, design information systems, train users, and plan e-commerce Web sites. 2054