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© 2001 Business & Information Systems 2/e2 Chapter 13 Developing and Managing Information Systems

© 2001 Business & Information Systems 2/e3 Our Agenda People in Information Systems Development The System Development Process System Development Tools A Case Study of Information Systems Development Other System Development Approaches

© 2001 Business & Information Systems 2/e4 Our Agenda (cont’d.) Individual Information Systems Development Electronic Commerce Systems Development Business Process Reengineering

© 2001 Business & Information Systems 2/e5 Learning Objectives Explain the roles of the people who are involved in information system development. Outline the phases and steps in the information system development process.

© 2001 Business & Information Systems 2/e6 Learning Objectives (cont’d.) Describe the user’s involvement in each phase of the system development process. Explain the purpose of common tools used for system development. Explain the use of prototyping and rapid application development in system development.

© 2001 Business & Information Systems 2/e7 Learning Objectives (cont’d.) Explain how the system development process can be adapted to the development of individual information systems. Describe the process of developing electronic commerce systems. Describe the purpose of business process reengineering.

© 2001 Business & Information Systems 2/e8 People in Information System Development Developing and Managing Information Systems

© 2001 Business & Information Systems 2/e9 People in Information Systems Development Systems analysts follow a step-by-step process to develop information systems. Information systems are usually developed by a group of people who form a project team.

© 2001 Business & Information Systems 2/e10 The System Development Process Developing and Managing Information Systems

© 2001 Business & Information Systems 2/e11 The Systems Development Process The system development process, which also called the System Development Life Cycle (SDLC) is divided into five main phases: 1.System planning 2.System analysis 3.System design 4.System implementation 5.System maintenance

© 2001 Business & Information Systems 2/e12 System Planning System planning is the phase in which the systems analyst decides whether a new information system should be developed. The systems analyst conducts a feasibility analysis. A cost/benefit analysis is prepared.

© 2001 Business & Information Systems 2/e13 System Analysis During system analysis, the analyst studies the existing and determines what the new system must do. Develop user requirements Develop a conceptual design Evaluate hardware and software alternatives Packaged software Custom software

© 2001 Business & Information Systems 2/e14 System Design During system design, the analyst specifies how the new system will function. Understanding what the new system must do Understanding how the system will do it Describing design details including layouts of screens, forms and reports; specifications for all hardware; descriptions of all programs.

© 2001 Business & Information Systems 2/e15 System Implementation During system implementation, the systems analyst acquires the components of the system – such as programs – tests the system, and changes over to the new system.

© 2001 Business & Information Systems 2/e16 System Implementation (cont’d.) Four methods of converting to the new system: Plunge – old system is turned off, new one is turned on. Phased – new system is divided into parts with one part phased in at a time. Pilot – new system is installed in a part of the organization. Parallel – old and new systems are used simultaneously for a period of time.

© 2001 Business & Information Systems 2/e17 System Maintenance System maintenance involves modifying the system during its life to meet new requirements. Maintenance is required for three reasons: 1.Errors found that were not detected in testing 2.A new function is to be added to the system 3.The requirements have changed

© 2001 Business & Information Systems 2/e18 System Development Tools Developing and Managing Information Systems

© 2001 Business & Information Systems 2/e19 System Development Tools Data Flow Diagrams (DFD) Entity-Relationship diagram (ER) CASE tools

© 2001 Business & Information Systems 2/e20 Data Flow Diagrams A tool many analysts use to show the flow of data in an information system. The diagram uses symbols with different shapes to indicate how data flows in the system. They are: Process – a rounded corner rectangle External entity – a rectangle Data store – an open rectangle Data flow – an arrow

© 2001 Business & Information Systems 2/e21 Entity-Relationship Diagram An entity is something about which data is stored in a database. A relationship is an association between entities. An entity-relationship diagram shows the entities and relationships between entities in a database.

© 2001 Business & Information Systems 2/e22 CASE Tools CASE – Computer Aided Software Engineering – tools are computer based tools such as those for system development.

© 2001 Business & Information Systems 2/e23 A Case Study in Information System Development Developing and Managing Information Systems

© 2001 Business & Information Systems 2/e24 A Case Study in Information Systems Development Sportswear Enterprises is considering requesting a sales system analysis. The case study considers the five steps in the system development life cycle.

© 2001 Business & Information Systems 2/e25 Other System Development Approaches Developing and Managing Information Systems

© 2001 Business & Information Systems 2/e26 Other System Development Approaches Three alternative approaches to developing information systems: Prototyping Rapid Application Development (RAD) Object-oriented analysis and design

© 2001 Business & Information Systems 2/e27 Prototyping Prototyping involves the systems analyst obtaining informal and incomplete requirements for the system and developing a prototype, which is a partial version of the system that acts like the real system but may not perform all the required functions of the system.

© 2001 Business & Information Systems 2/e28 Rapid Application Development Prototyping is used to determine user requirements. CASE tools speed up the analysis and design. The prototype is often developed into the final system. Significant user involvement is required.

© 2001 Business & Information Systems 2/e29 Object-Oriented Analysis and Design Object-oriented analysis and design involves combining the data and processing methods usually specified in the DFD and ER diagrams respectively. They are combined to form an object.

© 2001 Business & Information Systems 2/e30 Individual Information System Development Developing and Managing Information Systems

© 2001 Business & Information Systems 2/e31 Individual Information System Development The five steps of the SDLC serve as a general guide. Individual information system planning starts when the user recognizes a problem or a need. Must consider whether personal technical skills are adequate.

© 2001 Business & Information Systems 2/e32 Electronic Commerce System Development Developing and Managing Information Systems

© 2001 Business & Information Systems 2/e33 Electronic Commerce System Development While similar to the steps in the SDLC, there are notable differences: In e-commerce systems, the main user is the customer. Software selection is limited to the special e-commerce software.

© 2001 Business & Information Systems 2/e34 Electronic Commerce System Development (cont’d.) Design of an e-commerce system involves two main parts: Front end – is what the customer sees when they use the system. Back end – provides the capabilities necessary for completing the customer’s order including inventory control and product distribution.

© 2001 Business & Information Systems 2/e35 Electronic Commerce System Development (cont’d.) Publishing the system is the process of setting up the system on a server and making it available through the Internet.

© 2001 Business & Information Systems 2/e36 Business Process Reengineering Developing and Managing Information Systems

© 2001 Business & Information Systems 2/e37 Business Process Reengineering Business Process Reengineering (BPR) involves completely redesigning the business processes, which are groups of activities or tasks that accomplish things for a business. BPR is not gradual improvement, but rather radical redesign of business processes.

© 2001 Business & Information Systems 2/e38 Developing and Managing Information Systems Key Terms

© 2001 Business & Information Systems 2/e39 Key Terms Business Process Business Process Reengineering (BPR) CASE Conceptual Design Cost/Benefit Analysis Data Flow Diagram (DFD) Entity-Relationship (ER) Diagram Feasibility Analysis Legacy System Object-Oriented Analysis and Design Outsourcing Packaged Software Project Team

© 2001 Business & Information Systems 2/e40 Key Terms (cont’d.) Prototype Prototyping Rapid Application Development (RAD) System Analysis System Design System Development Life Cycle (SDLC) System Implementation System Maintenance System Planning Systems Analysis User Requirements

© 2001 Business & Information Systems 2/e41 Summary People in Information Systems Development The System Development Process System Development Tools A Case Study of Information Systems Development Other System Development Approaches

© 2001 Business & Information Systems 2/e42 Summary (cont’d.) Individual Information Systems Development Electronic Commerce Systems Development Business Process Reengineering

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