1. Chapter 1 Introduction to Systems Design and Analysis Systems Analysis and Design Kendall and Kendall Sixth Edition

2. 1-2 Readings & Major Topics Readings Chapter 1 (p. 1) in the textbook Major Topics Information systems SDLC (Systems Development Life Cycle) Phases of analysis and design CASE tools

3. 1-3 Information What is information? Domain dependent Facts, concepts, or instructions; any sort of knowledge or supposition which can be communicated. Information Must be managed as carefully as other resources (e.g., raw material, labor) Costs are associated with information processing Production, distribution, security, storage, retrieval, … Information processing must be managed to take full advantage of its potential

4. 1-4 Systems Analysis & Design Goals Analyze data input, processing or transforming data, data storage, and information output within the context of a particular business Analyze, design, and implement improvements in the functioning of a business via the use of computerized information systems

5. 1-5 How can we Analyze and Design Systems? Intuitive approach Pros and Cons? Systematic approach Pros and cons?

6. 1-6 Systems Analysis and Design in this Course Systematic approach to identifying problems, opportunities, and objectives; analyzing the information flows in organizations; and designing computerized information systems to solve a problem

7. 1-7 Systems Analyst Performs systems analysis and design Assesses how businesses function by examining the inputting and processing of data and the outputting of information with the intent of improving organizational processes

8. 1-8 Different Types of Systems Analysts Two major types Outside consultants to businesses Hired specifically to address information systems issues within a business Supporting experts (within a business you are regularly employed) Not a full-blown systems project, but rather entails a small modification or decision affecting a single department Your role as a systems analyst: agent of change Catalyst for change (i.e., improvements to the business that can be done via information systems)

9. 1-9 Interactions of a Systems Analyst A systems analyst interacts with users at different levels in the organization User managers Operations workers Systems managers Systems designers Programmers ….

10. 1-10 Qualities of a Systems Analyst Analysts are problem solvers. Communication skills Analysts must be ethical with users and customers ACM’s (Association of Computing Machinery) code of ethics … respect the privacy of others Give comprehensive and thorough evaluations of computer systems and their impacts, including analysis of possible risks …..

11. 1-11 Systems Development Life Cycle (SDLC) SDLC is a systematic approach to solving business problems It is divided into seven phases Each phase has unique activities A phase is never accomplished as a separate phase Several activities can occur simultaneously Activities may be repeated

12. 1-12 SDLC Overview

13. 1-13 Phase 1: Identifying problems, opportunities, and objectives Identifying Problems: don’t want to address the wrong problems Opportunities: situations that can be improved Objectives: how can the organization reach its objectives via computerized IS Personnel involved Analyst User managers Systems managers

14. 1-14 Phase 2: Determining Information Requirement Understand how the business functions and have complete information on the people, goals, data, and procedures Interview management, operations personnel Gather systems/operating documents Use questionnaires Observe the system and personnel involved Learn the details of the current system functions: who (people involved), what (business activities), where (environment in which the work takes place), when (timing), how (procedures), and the why (why is it done this way)

15. 1-15 Phase 2: Determining Information Requirement (cont’d) Personnel involved Analyst User managers Operations workers Systems managers Information Analyst (phases 1 and 2)

16. 1-16 Phase 3: Analyzing Systems Needs Analyzing systems needs Create data flow diagrams Document procedural logic for data flow diagram processes Complete the data dictionary Analyze structured decisions Make semistructured decisions (decisions taken under risk) Prepare and present the system proposal Recommend the optimal solution to management

17. 1-17 Phase 3: Analyzing Systems Needs (cont’d) Analyst makes recommendations to management Management decide whether to continue or not Personnel involved Analyst User managers Systems managers

18. 1-18 Phase 4: Designing the Recommended System Accomplish the logical design of the information system Design the user interface Design output Design input Design files and/or database Design control and backup procedures Produce decision trees or tables Produce program specifications

19. 1-19 Phase 4: Designing the Recommended System (cont’d) Personnel involved Analyst System designer User managers Operations workers Systems managers

20. 1-20 Phase 5: Developing and Documenting Software Develop any original software that is needed Design computer programs using structure charts, Nassi-Schneiderman charts, and pseudocode Walkthrough program design Write computer programs Document software with help files, procedure manuals, and Web sites with Frequently Asked Questions (FAQs)

21. 1-21 Phase 5: Developing and Documenting Software (cont’d) Personnel involved Analyst System designer Programmers Systems managers

22. 1-22 Phase 6: Testing and Maintaining the system Maintenance: starts in phase 6 but carried out routinely throughout the life of the IS Time spent on maintenance typically ranges from 48- 60 percent of total time System maintenance is Removing undetected errors, and Enhancing existing software Personnel involved Analyst System designer Programmers Systems management

23. 1-23 System Enhancements Systems are enhanced for the following reasons: Adding additional features to the system Business and governmental requirements change over time Technology, hardware, and software are rapidly changing

24. 1-24 Phase 7: Implementing and Evaluating the System Implementing and evaluating the system Plan conversion from the old system to the new one Train users Purchase and install new equipment Convert files Install system Review and evaluate system: whether the intended users are indeed using the system

25. 1-25 Phase 7: Implementing and Evaluating the System (cont’d) Personnel involved Analyst System designer Programmers User managers Operations workers Systems managers

26. 1-26 CASE Tools Computer-Aided Software Engineering (CASE) CASE tools are automated, microcomputer-based software packages for systems analysis and design Four reasons for using CASE tools are: To increase analyst productivity Facilitate communication among analysts and users Providing continuity between life cycle phases To assess the impact of maintenance

27. 1-27 CASE Tool Categories CASE tools may be divided into several categories Upper CASE (also called front-end CASE) tools, used to perform analysis and design Lower CASE (also called back-end CASE). These tools generate computer language source code from CASE design Integrated CASE, performing both upper and lower CASE functions

28. 1-28 Upper CASE Upper CASE tools Create and modify the system design Store data in a project repository The repository is a collection of records, elements, diagrams, screens, reports, and other project information These CASE tools model organizational requirements and define system boundaries

29. 1-29 Lower CASE Lower CASE tools generate computer source code from the CASE design Source code may usually be generated in several languages

30. 1-30 Lower CASE: Advantages of Generating Code Time to develop new systems decreases The time to maintain generated code is less than to maintain traditional systems Computer programs may be generated in more than one language CASE design may be purchased from third- party vendors and tailored to organizational needs Generated code is free from program coding errors

31. 1-31 Reverse Engineering Reverse engineering is generating the CASE design from computer program code Source code is examined, analyzed, and converted into repository entities Uses Computer-Assisted Reengineering (CARE) software

32. 1-32 Reverse Engineering Produces Depending on the tool set used: Data structures and elements, describing the files, records, and field Screen designs, if the program is online Report layouts for batch programs A structure chart showing the hierarchy of the modules in the program Database design and relationships

33. 1-33 Advantages of Reverse Engineering It has the following advantages: Reduced system maintenance time Program documentation is produced for loosely documented programs Structured programs may be generated from unstructured, older programs Future system maintenance is easier to implement Unused portions of programs may be eliminated