Information systems


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Information systems

  1. 1. Major Topics <ul><li>Information systems </li></ul><ul><li>Integrating New Technology </li></ul><ul><li>Phases of analysis and design </li></ul><ul><li>System maintenance </li></ul><ul><li>CASE tools </li></ul>
  2. 2. Information <ul><li>Information is an organizational resource which must be managed as carefully as other resources </li></ul><ul><li>Costs are associated with information processing </li></ul><ul><li>Information processing must be managed to take full advantage of its potential </li></ul>
  3. 3. Categories <ul><li>Eight categories of Information systems: </li></ul><ul><ul><ul><li>Transaction processing systems (TPS) </li></ul></ul></ul><ul><ul><ul><li>Office automation systems (OAS) </li></ul></ul></ul><ul><ul><ul><li>Knowledge work systems (KWS) </li></ul></ul></ul><ul><ul><ul><li>Management information systems (MIS) </li></ul></ul></ul><ul><ul><ul><li>Decision support systems (DSS) </li></ul></ul></ul><ul><ul><ul><li>Expert systems (ES) </li></ul></ul></ul><ul><ul><ul><li>Group decision support systems (GDSS) </li></ul></ul></ul><ul><ul><ul><li>Executive support systems (EES) </li></ul></ul></ul>
  4. 4. Level of Categories <ul><li>Figure 1.1 :The computer </li></ul><ul><li>analyst may be involved </li></ul><ul><li>with any of or all these </li></ul><ul><li>systems </li></ul>
  5. 5. Transaction Processing Systems (TPS) <ul><li>TPS are computerized information systems developed to process large amount of data for routine business transactions </li></ul><ul><li>TPS reduces the time once required to perform the task manually </li></ul><ul><li>TPS permits the organization to interact with external environment </li></ul><ul><li>Example: Inventory or Payroll system </li></ul>
  6. 6. Office Automation Systems (OAS) and Knowledge Work Systems (KWS) <ul><li>Office Automation Systems (OAS): </li></ul><ul><ul><li>Includes analysis of information so as to transform data or manipulate it in some way before sharing or formally disseminating it </li></ul></ul><ul><ul><li>Example: Word processing, spreadsheets, desktop publishing, electronic scheduling, communication through voice email, email and voice conference etc. </li></ul></ul><ul><li>Knowledge Work Systems (KWS): </li></ul><ul><ul><li>Supports professionals (scientists, engineers, doctors) by aiding them to create new knowledge </li></ul></ul><ul><ul><li>Example: Scientific analysis </li></ul></ul>
  7. 7. Management Information Systems (MIS) <ul><li>MIS supports broader spectrum of organizational tasks than TPS, including decision analysis and decision making </li></ul><ul><li>MIS users share a common database to access information </li></ul><ul><li>MIS outputs information that is used in decision making </li></ul><ul><li>Example: Account management system of Internet users </li></ul>
  8. 8. Decision Support systems (DSS) <ul><li>DSS is similar to the traditional MIS because they both depend on a database as a source of data </li></ul><ul><li>Again, DSS departs from MIS in that DSS emphasizes the support of decision making in all its phases </li></ul><ul><li>Example: Production increase decision by trend analysis </li></ul>
  9. 9. Expert Systems <ul><li>Expert system is a very special class of information system which is capable of generating solutions to problems with the aid of Artificial Intelligence (AI) </li></ul><ul><li>An expert system (also called a knowledge based system) uses the knowledge of an expert for solving a particular problem </li></ul><ul><li>Example: News Categorization software </li></ul>
  10. 10. Group Decision Support Systems (GDSS) and Computer Supported Collaborative Work Systems (CSCWS) <ul><li>Group Decision Support Systems </li></ul><ul><ul><li>GDSS are intended to bring a group together to solve a problem with the help of various support such as polling, questionnaires, brainstorming etc. </li></ul></ul><ul><li>Computer Supported Collaborative Work Systems </li></ul><ul><ul><li>CDCWS is a more general term of GDSS </li></ul></ul><ul><ul><li>CSCWS may include software support called “ groupware ” for team collaboration via network computers </li></ul></ul><ul><li>Example: video conferencing and web survey system </li></ul>
  11. 11. Executive Support Systems (ESS) <ul><li>It helps executives to make decisions on strategic level </li></ul><ul><li>It may provide graphical representation and communication support at board meeting required to make strategic decision </li></ul><ul><li>Example: New product launching decision </li></ul>
  12. 12. Integrating New Technologies <ul><li>New technologies are being integrated into traditional systems </li></ul><ul><ul><ul><li>E-commerce uses the Web to perform business activities </li></ul></ul></ul><ul><ul><ul><li>Enterprise Resource Planning (ERP) has the goal of integrating many different information systems within the corporation </li></ul></ul></ul><ul><ul><ul><li>Wireless and handheld devices, including mobile commerce (m-commerce) </li></ul></ul></ul><ul><ul><ul><li>Open source software </li></ul></ul></ul>
  13. 13. Integrating New Technologies <ul><li>Figure 1.2: Integrating </li></ul><ul><li>Technologies </li></ul>
  14. 14. E-Commerce Application and Web Systems <ul><li>Many businesses has found The Internet as </li></ul><ul><li>their most favored way to pursue business </li></ul><ul><li>growth because of the following advantages: </li></ul><ul><ul><li>Increase awareness of the availability of the service, product, industry, person, or group </li></ul></ul><ul><ul><li>24-hour access for users </li></ul></ul><ul><ul><li>Standardizing the design of interface </li></ul></ul><ul><ul><li>Creating a global system rather than remain local </li></ul></ul>
  15. 15. Enterprise Resource Planning (ERP) Systems <ul><li>Many organizations predicts potential benefits from the integration of many information systems existing on different management levels. </li></ul><ul><li>ERP systems are designed to perform this integration </li></ul><ul><li>Example: SAP, PeopleSoft and packages from Oracle </li></ul>
  16. 16. Systems for Wireless and Handheld Devices <ul><li>System analyst may be asked to design standard or wireless communication network that integrate voice, video and email into organizational intranet </li></ul><ul><li>System analyst may also be asked to develop intelligent agents to assist the user of PDA or cell phone </li></ul><ul><li>Wireless communication is referred as m-commerce (mobile commerce) </li></ul>
  17. 17. Open Source Software <ul><li>An alternative of traditional software development (where proprietary code is hidden from the users) is called open source software </li></ul><ul><li>Open source software is free to distribute, share and modify its source code </li></ul><ul><li>It makes money by providing services, customized program and support. </li></ul><ul><li>Open source software are widely used in handheld and mobile devices. </li></ul><ul><li>Example: Linux Operating System </li></ul><ul><li> Apache Web Server </li></ul>
  18. 18. Nature of Analysis and Design <ul><li>A systematic approach to: </li></ul><ul><ul><li>identify problems, opportunities, and objectives; </li></ul></ul><ul><ul><li>analyze the information flows in organizations; and </li></ul></ul><ul><ul><li>design computerized information systems to solve a problem. </li></ul></ul>
  19. 19. Systems Analyst <ul><li>Systems analysts act as: </li></ul><ul><ul><li>Outside consultants to businesses </li></ul></ul><ul><ul><li>Supporting experts within a business </li></ul></ul><ul><ul><li>Change agents </li></ul></ul><ul><li>Analysts are problem solvers, and require communication skills </li></ul><ul><li>Analysts must be ethical with users and customers </li></ul>
  20. 20. Systems Development Life Cycle (SDLC): <ul><li>SDLC is a systematic approach for solving business problems. </li></ul><ul><li>It is divided into seven phases. </li></ul><ul><li>Although each phase is presented discretely, it is never accomplished as a separate step. Instead separate activity can occur simultaneously </li></ul>
  21. 21. Systems Development Life Cycle (SDLC): <ul><li>Figure 1.3: Phases of SDLC </li></ul>
  22. 22. Phase 1: Identifying Problems, Opportunities and Objectives <ul><li>Personnel involved: </li></ul><ul><ul><li>Analyst </li></ul></ul><ul><ul><li>User management </li></ul></ul><ul><ul><li>System management </li></ul></ul><ul><li>Activities: </li></ul><ul><ul><li>Interviewing user management </li></ul></ul><ul><ul><li>Summarizing the knowledge obtained </li></ul></ul><ul><ul><li>Estimating the scope of the project </li></ul></ul><ul><ul><li>Documenting the results </li></ul></ul><ul><li>Output: Feasibility report containing problem definition and </li></ul><ul><li>objectives </li></ul><ul><li>Decision: Management then make decision whether to proceed with </li></ul><ul><li>the proposal or not </li></ul>
  23. 23. Phase 2: Determining Information Requirement <ul><li>Personnel Involved: </li></ul><ul><ul><li>Information Analyst (IA) </li></ul></ul><ul><ul><li>User: operation managers and operation workers </li></ul></ul><ul><ul><li>Systems management </li></ul></ul><ul><li>Activity: </li></ul><ul><ul><li>Interview management, operations personnel </li></ul></ul><ul><ul><li>Gather systems/operating documents </li></ul></ul><ul><ul><li>Use questionnaires </li></ul></ul><ul><ul><li>Observe the system and personnel involved </li></ul></ul><ul><ul><li>Learn the who, what, where, when, and how, and the why for each of these </li></ul></ul><ul><li>Output: Analyst understands how the business functions and gets enough information about the people, goals, </li></ul><ul><li>data and procedure involved </li></ul>
  24. 24. Phase 3: Analyzing System Needs <ul><li>Personnel Involved: </li></ul><ul><ul><li>Analyst (IA) </li></ul></ul><ul><ul><li>User management </li></ul></ul><ul><ul><li>Systems management </li></ul></ul><ul><li>Activity: </li></ul><ul><ul><li>Create data flow diagrams </li></ul></ul><ul><ul><li>Document procedural logic for data flow diagram processes </li></ul></ul><ul><ul><li>Complete the data dictionary </li></ul></ul><ul><ul><li>Make semi-structured decisions (condition alternatives) </li></ul></ul><ul><ul><li>Prepare and present the system proposal </li></ul></ul><ul><ul><li>Recommend the optimal solution to management </li></ul></ul>
  25. 25. Phase 4: Designing the Recommended System <ul><li>Personnel involved </li></ul><ul><ul><li>Analyst </li></ul></ul><ul><ul><li>System designer </li></ul></ul><ul><ul><li>User: operation managers and operation workers </li></ul></ul><ul><ul><li>System management </li></ul></ul><ul><li>Activity: </li></ul><ul><ul><li>Design the user interface </li></ul></ul><ul><ul><ul><li>Design output </li></ul></ul></ul><ul><ul><ul><li>Design input </li></ul></ul></ul><ul><ul><li>Design system controls </li></ul></ul><ul><ul><li>Design files and/or database </li></ul></ul><ul><ul><li>Produce program specifications </li></ul></ul><ul><ul><li>Produce decision trees or tables </li></ul></ul><ul><ul><li>Backup procedure </li></ul></ul>
  26. 26. Phase 5: Developing and Documenting Software <ul><li>Personnel involved </li></ul><ul><ul><li>Analyst </li></ul></ul><ul><ul><li>System designer </li></ul></ul><ul><ul><li>Programmers </li></ul></ul><ul><ul><li>Systems management </li></ul></ul><ul><li>Activity: </li></ul><ul><ul><li>System analyst designs computer programs using structure charts, and pseudo code etc. </li></ul></ul><ul><ul><li>Programmers write computer programs </li></ul></ul><ul><ul><li>Document software with help files, procedure manuals, and Web sites with Frequently Asked Questions </li></ul></ul>
  27. 27. Phase 6: Testing and Maintaining the System <ul><li>Personnel involved </li></ul><ul><ul><li>Analyst </li></ul></ul><ul><ul><li>System designer </li></ul></ul><ul><ul><li>Programmers </li></ul></ul><ul><ul><li>Systems management </li></ul></ul><ul><li>Activity: </li></ul><ul><ul><li>Test and debug computer programs </li></ul></ul><ul><ul><li>Test the computer system </li></ul></ul><ul><ul><li>Enhance system </li></ul></ul><ul><ul><li>Maintenance of the system begins from this phase </li></ul></ul>
  28. 28. Phase 7: Implementing and Evaluating the System <ul><li>Personnel involved: </li></ul><ul><ul><li>Analyst </li></ul></ul><ul><ul><li>System designer </li></ul></ul><ul><ul><li>Programmers </li></ul></ul><ul><ul><li>User: operation managers and operation workers </li></ul></ul><ul><ul><li>Systems management </li></ul></ul><ul><li>Activity: </li></ul><ul><ul><li>Train users </li></ul></ul><ul><ul><li>Analyst plans smooth conversion from old system to new system </li></ul></ul><ul><ul><li>Purchase and install new equipment </li></ul></ul><ul><ul><li>Install system </li></ul></ul><ul><ul><li>Review and evaluate system </li></ul></ul>
  29. 29. Maintenance <ul><li>Maintenance is performed for 2 reasons: </li></ul><ul><ul><li>System maintenance </li></ul></ul><ul><ul><ul><li>Removing undetected errors, and </li></ul></ul></ul><ul><ul><ul><li>Enhancing existing software </li></ul></ul></ul><ul><ul><li>Systems are enhanced for the following reasons: </li></ul></ul><ul><ul><ul><li>Adding additional features to the system </li></ul></ul></ul><ul><ul><ul><li>Business and governmental requirements change over time </li></ul></ul></ul><ul><ul><ul><li>Technology, hardware, and software are rapidly changing </li></ul></ul></ul>
  30. 30. Impact of Maintenance <ul><li>Figure 1.4: Time spent on system maintenance </li></ul>
  31. 31. Impact of Maintenance Figure 1.5: Resource consumption over the system life
  32. 32. CASE Tools <ul><ul><li>CASE tools are automated, microcomputer-based software packages for systems analysis and design </li></ul></ul><ul><ul><li>Four reasons for using CASE tools are: </li></ul></ul><ul><ul><ul><li>To increase analyst productivity </li></ul></ul></ul><ul><ul><ul><li>Facilitate communication among analysts and users </li></ul></ul></ul><ul><ul><ul><li>Providing continuity and integrity among life cycle phases </li></ul></ul></ul><ul><ul><ul><li>To assess the maintenance changes </li></ul></ul></ul>
  33. 33. CASE Tool Categories <ul><li>CASE tools may be divided into several categories </li></ul><ul><ul><li>Upper CASE (also called front-end CASE) tools, used to perform analysis and design </li></ul></ul><ul><ul><li>Lower CASE (also called back-end CASE). These tools generate computer language source code from CASE design. </li></ul></ul><ul><ul><li>Integrated CASE, performing both upper and lower CASE functions. </li></ul></ul>
  34. 34. Upper CASE <ul><li>Upper CASE tools </li></ul><ul><ul><li>Create and modify the system design </li></ul></ul><ul><ul><li>Store data in a project repository </li></ul></ul><ul><ul><li>The repository is a collection of records, elements, diagrams, screens, reports, and other project information </li></ul></ul><ul><ul><li>These CASE tools model organizational requirements and define system boundaries </li></ul></ul>
  35. 35. Upper Case <ul><li>Figure 1.6: The repository concept </li></ul>
  36. 36. Lower CASE <ul><li>Lower CASE tools generate computer source code from the CASE design </li></ul><ul><li>Source code may usually be generated in several languages </li></ul><ul><li>Advantages of generation code: </li></ul><ul><ul><li>decrease development time </li></ul></ul><ul><ul><li>More programming language support </li></ul></ul><ul><ul><li>Free from program coding error </li></ul></ul>
  37. 37. Traditional VS Case system development life cycle Figure 1.7: Traditional VS Case SDLC
  38. 38. Reverse Engineering <ul><li>Reverse engineering is generating the CASE design from computer program code </li></ul><ul><li>Source code is examined, analyzed, and converted into repository entities </li></ul>
  39. 39. Advantages of Reverse Engineering <ul><ul><li>Reduced system maintenance time, freeing up time for new development </li></ul></ul><ul><ul><li>Program documentation is produced for loosely documented programs </li></ul></ul><ul><ul><li>Structured programs may be generated from unstructured, older programs </li></ul></ul><ul><ul><li>Future system maintenance is easier to implement </li></ul></ul><ul><ul><li>Unused portions of programs may be eliminated </li></ul></ul>
  40. 40. Object-Oriented Analysis and Design <ul><li>Object-oriented (O-O) analysis and design is used to build object-oriented programs </li></ul><ul><li>This includes not only data but the instructions about operations that manipulate the data </li></ul>
  41. 41. Alternative Methodologies <ul><li>Alternatives to SDLC: </li></ul><ul><ul><li>Prototyping </li></ul></ul><ul><ul><li>ETHICS </li></ul></ul><ul><ul><li>Soft System Methodology </li></ul></ul><ul><ul><li>Multiview </li></ul></ul>1.