Classic Model Part II


Verification and Validation of Requirement Specifications (I)


Verification and Validation of Requirement Specifications (II)

internal traceability

external traceability

functional testing

requirement review or walkthroughs


Other Points


No Silver Bullet


Two kinds of Problems

high-level programming languages

unified programming environments

time-sharing machines


False Silver Bullets


What about Java and the Internet/Intranet ?


Stuffs Worth Repeating

divide and conquer



explicit representation of complex relationships

verification and validation



Boehm’s Top Ten List

  1. Finding and fixing a software problem after delivery is 100 times more expensive than finding and fixing it during the requirement and design phases.

  2. You can compress a software development schedule upto 25% of nominal but no more.

  3. For every dollar you spend on software development you will spend two dollars on software maintenance.

  4. Software development and maintenance techniques are primarily a function of the number of source instruction in the product.

  5. Variation between people account for the biggest difference in software productivity.

  6. The overall ratio of computer software to hardware costs has gone from 15:85 in 1955 to 85:15 in 1985, and it is still growing.

  7. Only about 15% of software product-development effort is devoted to programming.

  8. Software systems and software products each typically cost three times as much per instruction to fully develop as does an individual software program. Software systems products cost nine times as much.

  9. Walkthroughs catch 60% of the faults.

  10. Many software phenomena following a Pareto distribution: 80% of the contribution comes from 20% of the contributors.

20% of modules contribute 80% of faults

20% of modules contribute 80% of costs

20% of faults consume 80% of the cost to fix them

20% of modules consume 80% of execution time

20% of tools experience 80% of tool usage


80% of code was done by 20% of programmers

80% of faults was made by 20% programmers

20% of engineers contribute 80% of tasks


Recent Trends


Internet and Intranet Again


Applications of Internet/Intranet


Java and Java


More Ideas


Component Engineering/Frameworks


Let's Talk About Our Projects !



All materials are from work experience, software engineering books and ideas & notes from my advisor in University of Minnesota