Software Project Management: Top 10 list of Industrial Software Metric

To manage software project, we should know Top-Ten list of software metric relationships, in terms of their value in industrial situations. Here they are, in rough priority order:

1. Finding and fixing a software problem after delivery is 100 times more expensive than finding and fixing it during the requirements and early design phases.
2. You can compress a software development schedule up to 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 costs are primarily a function of the number of source instructions in the product.
5. Variations between people account for the biggest differences 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 3 times as much per instruction to fully develop as does an individual software program. Software system products cost 9 times as much.
9. Walkthroughs catch 60% of the errors.
10. Many software phenomena follow a Pareto distribution: 80% of the contribution comes from 20% of the contributors.

Source: INDUSTRIAL SOFTWARE METRICS: A TOP-TEN LIST by Barry W. Boehm, TRW Inc.