Cleanroom Software Engineering By NADEEM AHMED FROM DEPALPUR
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Cleanroom is a software development approach that emphasizes defect prevention over testing. It uses formal methods and statistical testing to develop reliable software in increments. Each increment undergoes requirements analysis, formal design, correctness verification, test planning and statistical testing before being certified and integrated into the overall system. This allows many components to be worked on concurrently, improving productivity while avoiding defects.
Cleanroom Software Engineering By NADEEM AHMED FROM DEPALPUR
- 1. What is cleanroom • It is a type of software development approach where most of the developers follow this approach to develop software with certified reliability. • This cleanroom deny the entry of defects during the development of software. • It avoids copyright infringement litigation. • Formal design and requirements methods.
- 2. Introduction • It is straight forward technique • CR is an approach that emphasis on developing quality software with the help of statistical and mathematical techniques. • In short verifying the correctness of every phase before testing. • It fully based on formal methods.
- 4. Why is it important • Quality • Most suitable for critical applications • Increased productivity • Reduces cost • Team oriented increment pipelining allows for many component to be worked on concurrently therefore increasing productivity.
- 6. Model….. • Cleanroom uses a specialized version of increment process applying pipelining techniques. • Each increment is eventually added together to create the entire system • Follows 7 steps process for each increment assuring that each component is certified reliable before moving on to the next component.
- 7. Cleanroom Methods Steps 1).Increment Modal 2).Requirement gathering 3).Box structure specification 4).Formal Design 5).Correctness verification 6).Statistical test planning 7).Statistical use testing
- 8. 1).Increment planning • Detail description of customer level requirement is described for each functional increment. • All the increment is defined and planned beginning to end. • It simplify the customer concepts.
- 10. 2).Requirement gathering • Requirement gathering is done by using the traditional techniques like analysis, design, code and test. • A more detailed description of the customer level requirement is developed.
- 11. 3).Box Structure Specification • Requirements have been established, the function and behavior of each increment must be defined. • It uses a box structure specification to defined the product. • The refining process begins from black box, refined to state box and then finally to clean box.
- 12. Box Structure…… Structure programing code Black Box State Box Clear Box
- 13. 3.1).The Black Box • It represents an incremental component as a whole and sits at the top of a hierarchy of software components. • The black box reacts to stimuli and uses transition mapping rules to determine a response.
- 14. 3.2).The State Box • It seen as generalized state machine including state data and operations and incorporated the black box. • It reacts to stimuli which causes a state transition and results in a response. • State boxes are crucial for showing the behavior of a system and how it reacts and transitions due to user inputs.
- 15. The state Box
- 16. 3.3).The clear Box • It breaks down the sub functions of the black box into procedural that resemble structure programing. • It shows the component in high detail. • At this stage,these specification are able to mathematically proven to be correct
- 17. 4).Formal Design • Once box the structure specification is complete cleanroom designing takes place. • Functions in clear box are systematically refined from mathematically functions to logical connectives that resemble to programing language.
- 18. 5).Correctness verification • It allow them to be mathematically verified for correctness using mathematical proofs. • Using general correctness condition depending on situation. • Once all functions of a component are verified to be correct, coding implementation can begin.
- 19. 6).Statistical test planning • Analyzed, planned and designed the projected Usage of the software. • The cleanroom activity is organized in parallel with specification, verification and code generation.
- 20. 7).Statistical use testing • The exhaustive testing of computer software of computer software is impossible. It is compulsory to design limited number of test cases. • These sample are collected from the users from a targeted population.
- 21. Certification • After the verification, inspection and correctness of all errors, the increment are certified and ready for integration.
- 22. Incrementation