1. Lecture 8 Is Software Different?
CSE 403
Spring 2005

2. Is Software Different? Compare with other engineering disciplines
Electronics, construction, aircraft
Answers that are possible
No,
Yes, but it shouldn’t be
Yes

3. Is software different? Is software less reliable?
Are software projects more likely to fail?
Is this just perception?

4. It’s not just software . . .

5. Is software different?
Is the fundamental nature of software different from physical artifacts?
Does it break differently?
Continuity argument – we know how to build tolerances into physical systems

6. Is software different?
Is the environment of use of software different?
Rapid technology change
Greater user modification
Hostile deployment scenarios

7. Is software different?
Is the culture of software development different?
Is the field immature?
Individual nature of writing software
Hacker culture
Developer Hubris – assumptions that things will work
Ease of modification
Low cost of failure

8. What responsibility do writers of software have?
What are the risks
What types of failures to anticipate

9. Should software engineers be licensed?
Case in favor
All other professions go through some certification, but anybody can write software
Potential impacts of bad software are severe
Professional certification can ensure training and ethical behavior
Can provide a mechanism for accountability

10. Software engineers: to license or not to license?
In 1998, Texas started requiring software engineers to be licensed as professional engineers
Is this a good idea, or not?

11. Goal of licensing?
The general goal of licensing is to protect the interests of the public when safety is at issue and when the public cannot make effective judgments on their own
Civil engineers to ensure building standards are met
Aeronautical engineers to ensure aircraft safety rules are met …
Many practicing engineers are licensed, especially civil and mechanical engineers
And many are not

12. Non-goals of licensing
Guarantees of high-quality products
Reducing costs of development
Guild protection

13. Other approaches to safety
Process-focused (CMM, capability-maturity model; ISO 9000)
Product-focused (pharmaceutical industry, …)

14. My views (Notkin)
Protecting the public where safety is concerned is a crucial goal
Licensing of software engineers cannot, at present, do that
In fact, it provides false guarantees to the public, which is totally inappropriate
Perhaps at some point we will have a standard of practice that is sufficient upon which to base licensing – but not yet!
Software is different – rapid and extensive change (both of the product and the underlying technologies) and the underlying mathematics are among the reasons

15. Some real dirt
Why professional licensing was pursued overall in software engineering
Why it was pursued in Texas