1. Introduction to Programming Design School of Business Eastern Illinois University © Abdou Illia, Spring 2003 (Week1, Wednesday 01/15/2003)

2. 2 Stars n Something to which you should pay special attention. n Multiple stars are for especially important or difficult material

3. 3 IS versus Computer science professionals Computer science IS professionals Computer science and electrical engineering students are trained to work in hardware and software vendor firms, such as Microsoft, IBM, Oracle, and Cisco Systems. IS students are trained to work in end user organizations, such as banks, government agencies, and manufacturing firms-- organizations that use Computer applications to get their work done

4. 4 The IS Job n To help firms make decisions about which kind of computer applications to purchase. n To do needs analysis n To plan and manage development of computer applications n To manage company’s computer applications portfolio.

5. 5 Learning Objectives (Relate to Course objectives 1-3) n Identify steps in the SDLC n State objectives of CASE tools n Name some tools & methodologies used in Structured Design

6. 6 The Idea behind Computer programs Input 40, 10 Processing 40 x 10 Output 400 Working hours = 40 Rate = 10 Pay = 400

7. 7 System Development Life Cycle n Series of well-defined steps followed – When system is created – When system is changed n Represent the big picture of what happens – During systems creation – During system modification

8. 8 FIGURE 1-1 System Development Life Cycle (SDLC), page 2 Marilyn Bohl and Maria Rynn Tools for Structured Design, Fifth Edition 1. Analyze the current system 2. Define the new system requirements 3. Design the new system 4. Develop the new system 5. Implement the new system 6. Evaluate the new system System Development Life Cycle

9. 9 Analyze the current system n Carefully study all aspects of the current system n Objectives: – Understand What things are done and how – Identify any problems associated with the system n Effective technique used: – Talk to users of the system

10. 10 Define the New System requirements n Specify What need to be done (not how to do it) n To be defined: – Input requirements (nature of data, source, etc.) – Processing requirements – Output requirements (Types of reports, content, etc.) – Storage requirements n State of Requirements (for Management decision)

11. 11 Design the New System n Using of the requirements defined to design the new or modified system n Job of the Analyst or the System designer n Use of CASE Tools – Computer-Assisted Software Engineering – Tools, methods, and procedures for system development

12. 12 Design the New System n Objectives of Using CASE tools: – Make the analyst/programmer’s job easier – Control over the process of system development – Improve analyst/programmer productivity – Improve program quality

13. 13 Example of CASE Tool: System flowchart SALES DATA WEEKLY SALES PROGRAM WEEKLY SALES REPORT PAYROLL PROGRAM PAYCHECKS PAYROLL SUMMARY REPORT PAYROLL EXCEPTION REPORT Program 1 Program 2 System Flowchart: Graphical representation of all programs within the system and how they interrelate

14. 14 Develop the new System n Coding programs n Job of programmers n Use of a series of well-defined steps called Program Development Cycle

15. 15 Figure 1-3 Program Development Cycle (PDC) Marilyn Bohl and Maria Rynn Tools for Structured Design, Fifth Edition 1. Review the input, processing, output and storage requirements 2. Develop the logic for the program 3. Write the program using a programming language 4. Test and debug the program 5. Complete the program documentation Program Development Cycle (PDC)

16. 16 Program Development Cycle (PDC) n Common tools used: – Program flowchart (Step __) – Pseudocode (Step __) – Hierarchy chart or Structure chart (Step __) – Code generator (Step __)

17. 17 Program flowchart & Pseudocode Program Flowchart: Graphical illustration of the problem-solving logic within a program Pseudocode: English-language statements that describe the processing steps of a program in paragraph form.

18. 18 Qualities of good programs n Reliability (produce what it is expected to) n Graphical User Interfaces (GUI) n User-friendly (ease of use)

19. 19 Qualities of good programs Figure 1-6: Sample Input Screen (Not User-Friendly) Figure 1-7: Sample Input Screen (User-Friendly)

20. 20 Summary Questions 1. (a) What is System Development Life Cycle? (b) Name steps in the SDLC. 2. Talking to users is an effective technique used in the early stages of the SDLC: T/F 3. (a) What does the acronym CASE stand for ? (b) Name three CASE tools used in the SDLC. 4. What is a Program Flowchart ? 5. Name two qualities of a good program 8 9 11,13,16 17 18

21. 21 System Development Life Cycle StepsKey actorsTools/Techniques 1. Analyze the current system Analyst, UsersInterviews, Users observation at work 2. Define New Syst. Requirements Analyst, Users, Management Interviews, Users observation at work 3. Design New SystemAnalyst (or system designer) CASE tools like System Flowchart Software 4. Dev. The New SystemProgrammersProgram Flowchart, Pseudocode, Hierarchy chart, Code generator, programming languages 5. Implement New Syst.Analyst, Users 6. Evaluate the New System Analyst, Users, Management