Software Development Life Cycle Notes

Programming Fund. With C

II sem Dept CSE

Programming Languages & Life Cycle of Software project Programming Languages :

Program : Series/Set of instructions / steps to solve a problem which can be used by Computer Programming Language : St of keywords and grammar for instructing a computer to perform specific task. Computer programs are written in a programming language Different types of programming Languages High level language C, C++, Basic, Java Assembly language

Machine language Hardware M/c Language : Consists of only zeros and ones, which computer can understand. It is m/c dependent Assembly Language :Consists of symbols / mnemonics which constitute instructions, It is m/c dependent High level Languages : it is simple and similar to natural language with some grammatical rules. It m/c independent C, C++, COBOL, Pascal, BASIC Machine and Assembly languages are called as Low level languages Generation of Languages Programming Languages evolved over a period of time. As programming concepts and technology changed, programming languages are also evolved Five Generations of Programming Language: 1. First generation – m/c language 2. Second generation – Assembly Language 3. Third generation – High level Language 4. Fourth generation – Programming Languages that are close to Human languages compared to HLL 5. Fifth generation – Languages used for AI (artificial Intellegence)and neural networks

Programming Fund. With C

II sem Dept CSE

Difference between Machine language and Assembly language : Machine Language

Assembly language

Instructions are in the form of 0’s & 1’s Instructions are in the form of Mnemonics/symbolic names Writing program, debugging and understanding is difficult

easy

Translator is not required

Translator(Assembler) is required to convert assembly language program to m/c language slower

Execution is faster

Differences between High level language and low level language High Level Language

Low level Language

m/c independent

m/c dependent

Uses English like instructions

Uses mnemonics

Writing program, debugging, understanding is easy

Difficult

Compiler/ Interpreter is used to Assembler is used to convert Assembly convert high level language to m/c language to m/c language language Execution is slower

Execution is faster

Life Cycle of Software project

Programming Fund. With C

Requirement Analysis

Design Testing

Build Coding Deployment

II sem Dept CSE

maintenance

Requirement Analysis : This phase is used to get the information about the project which helps in development of the project. To gather information following activities are carried out. • Interview the customer to know about his requirement. • Interview the Employees and higher officials . • Study the existing software if it exists. The output of this phase is “Requirement analysis document” which contains all the criteria that the system should meet. After reviewing by both customer and developer , it is to be signed by both. Design Phase: The Requirement Analysis document forms input to the design phase. Depending on the information collected an “outline” for software project is decided. This outline is documented in “High Level Design Document” which contains a representation or design of the system without its implementation details. It identifies the various components (modules) that forms the system and interactions between various components of the system. Using High level Design Document, “Detailed Design Document” is prepared. It contains specifications of how an individual module of the system will function in terms of data input and output. All the documents must be reviewed and signed by the customer before they are finalized. Build phase : In this phase , A software Engineer converts the detailed design into a working module by writing programs. The programs are written in the programming language. Software Engineer who has written the code has to perform “Unit test” to check the functionality within the module. If a Unit test fails, the defects have to be removed by the person who has written the code. The code is tested again. Testing Phase : The Unit tested code is integrated to form the Software project as specified in the design phase. In this phase , “Integration testing” and “System testing” is carried out. Integration

Programming Fund. With C

II sem Dept CSE

Testing tests the interaction between various modules. In System testing, the software project is tested as a whole for functionality and performance. Deployment Phase : During this phase, the error free and completed software project is deployed on the customer’s hardware. -----------------End-----------------

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