Lec 06
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- Words: 439
- Pages: 9
Wear vs. Deterioration increased failure rate due to side effects
Failure rate
change actual curve
idealized curve Time Dr. Arshad A. Shahid
37
NU Islamabad
Future of SE … • • • • • • • • • • • •
• • • • • • • • • • • •
Process Requirements engineering Reverse engineering Testing Maintenance and Evolution Software architecture OO Modeling SE and Middleware Tools and environments Configuration management (OO) Databases and SE SE Education
Dr. Arshad A. Shahid
38
Software analysis Formal specification Mathematical foundations Reliability and Dependability Performance SE for Safety SE for security SE for mobility SE & the Internet Software economics Empirical studies of SE Software metrics
NU Islamabad
Software Engineering Principles • Principles form the basis of methods, techniques, methodologies and tools • Seven important principles that may be used in all phases of software development • Apply to the software product as well as the development process
Dr. Arshad A. Shahid
39
NU Islamabad
Key principles 1. 2. 3. 4. 5. 6. 7.
Dr. Arshad A. Shahid
Rigor and formality Separation of concerns Modularity Abstraction Anticipation of change Generality Incrementality
40
NU Islamabad
as tees follow the defined steps and rules
1. Rigor and formality • Software engineering is a creative design activity, BUT It must be practiced systematically • Rigor is a necessary complement to creativity that increases our confidence in our developments • Formality is rigor at the highest degree
Dr. Arshad A. Shahid
41
NU Islamabad
Examples: Rigor and formality • Product: – Formal-Mathematical analysis of program correctness – Rigorous-Systematic test data derivation
• Process: – Rigorous- detailed documentation of each development step in waterfall model – Formal- automated transformational process to derive program from formal specifications Dr. Arshad A. Shahid
42
NU Islamabad
2. Separation of concerns • To dominate complexity, separate the issues to concentrate on one at a time – "Divide & conquer"
• Supports parallelization of efforts and separation of responsibilities
Dr. Arshad A. Shahid
43
NU Islamabad
Separation of concerns Examples: – Process: Go through phases one after the other as in waterfall Model –Does separation of concerns by separating activities with respect to time
– Product: Keep different types of product requirements separate –Functionality discussed separately from the performance constraints
Dr. Arshad A. Shahid
44
NU Islamabad
3. Modularity • A complex system may be divided into simpler pieces called modules • A system that is composed of modules is called modular • Supports application of separation of concerns – when dealing with a module we can ignore details of other modules Dr. Arshad A. Shahid
45
NU Islamabad
Failure rate
change actual curve
idealized curve Time Dr. Arshad A. Shahid
37
NU Islamabad
Future of SE … • • • • • • • • • • • •
• • • • • • • • • • • •
Process Requirements engineering Reverse engineering Testing Maintenance and Evolution Software architecture OO Modeling SE and Middleware Tools and environments Configuration management (OO) Databases and SE SE Education
Dr. Arshad A. Shahid
38
Software analysis Formal specification Mathematical foundations Reliability and Dependability Performance SE for Safety SE for security SE for mobility SE & the Internet Software economics Empirical studies of SE Software metrics
NU Islamabad
Software Engineering Principles • Principles form the basis of methods, techniques, methodologies and tools • Seven important principles that may be used in all phases of software development • Apply to the software product as well as the development process
Dr. Arshad A. Shahid
39
NU Islamabad
Key principles 1. 2. 3. 4. 5. 6. 7.
Dr. Arshad A. Shahid
Rigor and formality Separation of concerns Modularity Abstraction Anticipation of change Generality Incrementality
40
NU Islamabad
as tees follow the defined steps and rules
1. Rigor and formality • Software engineering is a creative design activity, BUT It must be practiced systematically • Rigor is a necessary complement to creativity that increases our confidence in our developments • Formality is rigor at the highest degree
Dr. Arshad A. Shahid
41
NU Islamabad
Examples: Rigor and formality • Product: – Formal-Mathematical analysis of program correctness – Rigorous-Systematic test data derivation
• Process: – Rigorous- detailed documentation of each development step in waterfall model – Formal- automated transformational process to derive program from formal specifications Dr. Arshad A. Shahid
42
NU Islamabad
2. Separation of concerns • To dominate complexity, separate the issues to concentrate on one at a time – "Divide & conquer"
• Supports parallelization of efforts and separation of responsibilities
Dr. Arshad A. Shahid
43
NU Islamabad
Separation of concerns Examples: – Process: Go through phases one after the other as in waterfall Model –Does separation of concerns by separating activities with respect to time
– Product: Keep different types of product requirements separate –Functionality discussed separately from the performance constraints
Dr. Arshad A. Shahid
44
NU Islamabad
3. Modularity • A complex system may be divided into simpler pieces called modules • A system that is composed of modules is called modular • Supports application of separation of concerns – when dealing with a module we can ignore details of other modules Dr. Arshad A. Shahid
45
NU Islamabad
