어쨌건간에 흘러가는 者

본 포스트는 개인 스터디 용으로 작성된 Ian Sommerville의 Software Engineering, 8/E의 요약본입니다.

1. Verification and formal methods
- Formal methods used on mathematical specification of the system
- Formal methods are the ultimate static verification technique
- They involve detailed mathematical analysis of the specification and any develop formal arguments that a program conforms to its mathematical specification

2. Formal methods pros/cons
pros:
- mathematical specification by detailed analysis likely to uncover errors
- detect implementation errors before testing when the program is analysed alongside the specification
cons:
- require specialised notations that cannot be understood by domain experts
- Very expensive to develop a specification
- It may be possible to reach the same level of confidence in a program more cheaply using other V&V techniques

3. Cleanroom S/W development
- The name is derived from the 'Cleanroom' process in semiconductor fabrication. The philosophy is defect avoidance rather than defect removal
- based on
  1) Incremental development
  2) Formal specification
  3) Static verification using correctness arguments
  4) Statistical testing to determine program reliability

4. Cleanroom process

5. Formal specification and inspections
- The state based model is a system specification and the inspection process checks the program against this model
- The programming approach is defined so that correspondence between the model and the system is clear
- Mathematical arguments (not proofs) are used to increase confidence in the inspection process

본 포스트는 개인 스터디 용으로 작성된 Ian Sommerville의 Software Engineering, 8/E의 요약본입니다.

1. Formal methods
- Formal specification is part of formal methods
- based on mathematical representation and analysis of S/W
- includes Formal specification, Specification analysis and proof, transformational development, program verification

2. Specification in the software process
- Specification and design are not seperatable.
- Architectural design is essential to specification process

3. Formal specification
- complements informal specification techniques. It removes areas of dout in a specification
- forces an analysis of the system requirements at an early stage, especially.
- Formal specification techniques are most applicable in the development of critical systems and standards.
- Algebraic techniques are suited to interface specification where the interfaces is defined as a set of object classes.
- Model-based techniques model the system using sets and functions. This simplifies some types of behavioural specification
- Operations are defined in a model-based specification by defining pre and post conditions on the system state.