1. Copyright©2008 N.AlJaffan®KSU1 Chapter 11 Information system development and programming language

2. Copyright©2008 N.AlJaffan®KSU2 Information system development System is a set of components that interact to achieve a common goal. System is a set of components that interact to achieve a common goal. Information system (IS) is a collection of HW, SW, data, people and procedures that work together to produce quality information. Chapter 11

3. Copyright©2008 N.AlJaffan®KSU3 Information system development System development cycle is a set of activities used to build an information system. System development cycle often organize activities by grouping them into larger categories called phases. Chapter 11

4. Copyright©2008 N.AlJaffan®KSU4 Most system development cycles contain 5 phases Most system development cycles contain 5 phases Chapter 11Analysis Planning Design Implementation Operation, Support and Security and Security Perform detailed analysis activities Study current systemStudy current system Determine user requirementsDetermine user requirements Recommend solutionRecommend solution Acquire HW and SW, if necessary Develop details of system Develop programs. Install and test new system Train users Review Project requestsReview Project requests Prioritize project requestPrioritize project request Allocate resourcesAllocate resources Form project development teamForm project development team Perform maintenance activities Monitor system performanceMonitor system performance Assess system securityAssess system security Conduct preliminary investigationConduct preliminary investigation

5. Copyright©2008 N.AlJaffan®KSU5 Information system development Who participates in the system development cycle?  Project team includes both nontechnical user and It professionals.  System analyst is designing and developing an information system.  Project leader one member of the team whose manages and controls the budget and schedule of the project. Chapter 11

6. Copyright©2008 N.AlJaffan®KSU6 Information system development Project management is the process of planning, scheduling and then controlling the activities during the system development cycle. is the process of planning, scheduling and then controlling the activities during the system development cycle.Documentation is the collection and summarization of data and information.  It includes reports, diagrams, programs or any other information generated during the system development cycle. Chapter 11

7. Copyright©2008 N.AlJaffan®KSU7 Programming Languages Computer program is a series of instruction that directs a computer to perform tasks. Computer programmer, some times called a developer, writes and modifies computer programs. Programming language is a set of words, symbols and codes that enables a programmer to communicate instructions to a computer. Chapter 11

8. Copyright©2008 N.AlJaffan®KSU8 Programming Languages Chapter 11 Two type of languages are low-level and high- level. Low-level language is a programming language that is machine dependent which runs on only one particular type of computer. High-level languages often are machine independent which runs on many different types of computers and operating systems.

9. Copyright©2008 N.AlJaffan®KSU9 Programming Languages Chapter 11 low-level languages Machine language Assembly language  Known as the first generation of programming language.  It is the only language the computer directly recognizes.  Instructions use a series of binary digits or a combination of numbers and letters that represents binary digits.

10. Copyright©2008 N.AlJaffan®KSU10 Programming Languages Chapter 11 Assembly language  Known as the second generation of programming language.  Programmer write instructions using symbolic instruction codes.  It can be difficult to learn.  The computer cannot execute the assembly source program.  Source program : is the program that contains the language codes.  To convert the assembly code into machine language, programmers use a program called an assembler

11. Copyright©2008 N.AlJaffan®KSU11 Programming Languages Chapter 11 Procedural Languages The disadvantages of low-level languages led to development of procedural languages.  Often called a third-generation languages (3GL).  Programmer uses a series of English-like word to write instructions and arithmetic symbols.

12. Copyright©2008 N.AlJaffan®KSU12 Programming Languages Chapter 11 Procedural Languages Programmers typically use either a compiler or an interpreter to perform the translation ( from source code to machine code).  Compiler is a separate program that converts the entire source program into machine language before executing it.  Interpreter reads a code statement converts it to one or more machine language instructions and then executes those instructions.

13. Copyright©2008 N.AlJaffan®KSU13 Programming Languages Chapter 11CompilerObjectProgramResultsSourceProgramData ProgramListing

14. Copyright©2008 N.AlJaffan®KSU14 Programming Languages Chapter 11 SourceProgramData Interpreter Results

15. Copyright©2008 N.AlJaffan®KSU15 Programming Languages Chapter 11 Procedural Languages  One advantage of an interpreter is that when it finds errors, it displays feedback immediately.  The disadvantage is that interpreted programs do not run as fast as compiled programs.  Example of procedural languages is COBOL and C.

16. Copyright©2008 N.AlJaffan®KSU16 Programming Languages Chapter 11 Object-Oriented Programming Languages  Programmers use an OOP language or OOP development tool to implement objects in a program.  Program development tool is a program that provides a user friendly environment for building programs.  A major benefit of OOP is the ability to reuse and modify existing objects.  Its work well in a RAD environment.  Example of OOP languages are Java, C++ and C#.

17. Copyright©2008 N.AlJaffan®KSU17 The program development cycle Chapter 11DesignSolution ValidateDesign ImplementDesignTestSolution DocumentSolution Analyze Requirements Requirements