This is the presentation file that generally accompanies the short course I teach on failures. For more info on the course, http://is.gd/things_break

1. When Things Break
Dr. Ron Graham, editor
a Clarity Strategic production

2. Contents

What is an engineering failure?

What are some examples?

What lessons can be learned?

How can failures be avoided?

Can engineered systems be truly “safe?”

Oh GOD! I've had a failure! What do I DO???
The conscientious, effective engineer is a virtuous engineer.
- Samuel Florman

3. What is an engineering failure?

failure (n) == malfunction + loss of opportunity

risk (n) == the chance of something going
wrong

hazard (n) == what happens if something goes
wrong

Murphy (n) == the guy who says something will
go wrong

bug (n) == what makes software not work as
advertised

4. What are some examples?

Tacoma Narrows Bridge

Space Shuttle Challenger

Kansas City Hyatt Regency skywalk

Union Carbide Bhopal, India

THERAC-25 radiation device
These are just a few of the popular examples – those students have really
responded to in the past.

5. What can be learned?

Better design techniques

Enhanced safety precautions

More rigorous testing (and simulation)

More enlightened management

Discovery of new failure modes (not just what
initiates the failure, but also what propagates it)

Better estimates of cost and risk
For we can demonstrate by geometry that the large machine is not
proportionately stronger than the small. - Galileo

6. How can failures be avoided?

Design

Redundancy and spare parts

Watch out for discontinuities and interfaces

Problems of scale (not just changing size)

Operation

Massive manned tests

Training and retraining (with updated manuals)

Carefully designed rules for alarms

7. How can failures be avoided?

Management

Exercise controls

Employ verification and validation

Pay attention to systems engineering

Maintenance

Examine repair v. replacement

Have procedures that disconnect energy

Examine self- and remote-test capability

8. How can failures be avoided?

Materials

Use materials well within their load limits

Production

Be sure equipment works properly and operators
are qualified

Use inspection and testing to separate defective
components (especially at fastened joints)

Adhere to relevant codes

9. Can engineered systems be truly
“safe?”

Make sure development and support staff are
not all the same people

Complete, timely, readable diagnostics

Backup “human-in-the-loop” options

Guard against power failure, surges, and EMI

Give yourself enough duty cycle for multiple
tasks

10. Can engineered systems be truly
“safe?” (Life or property at risk)

Redundant fastening to prevent collapse

Containment of explosions or hazardous flows

Adequate shielding

Sufficient alarms

Buffer zone between system and neighbors

Make dangerous releases or shrapnel dissipate
or reach a low-energy state quickly

11. Oh GOD! I've had a failure!
What do I DO???

Get hold of yourself

Prepare for a failure investigation – and LEARN
from it!

Be prepared for a critical look at

Your experience base

Safety margins

Self-limiting phenomena

Worst-case environments

The importance of observation

12. Sources

Casey, Set Phasers on Stun

Florman, The Civilized Engineer

Florman, The Existential Pleasures of Engineering

Jones, Engineering Materials 3: Materials Failure
Analysis – Case Studies and Design Implications

Kepner, The New Rational Manager

Kletz, What Went Wrong?

Kletz, An Engineer's View of Human Error

Kletz, Learning From Accidents

LaPierre and Moro, Five Past Midnight in Bhopal

Levy and Salvadori, Why Buildings Fall Down

Lovell and Kluger, Apollo 13

Murray and Cox, Apollo: The Race to the Moon

Nishida, Failure Analysis in Engineering Applications

Peterson, Fatal Defect: Chasing Killer Computer Bugs

Petroski, To Engineer is Human

Petroski, Design Paradigms: Case Histories of Error
and Judgment in Engineering

Rogers et. al. "Report to the President by
the Presidential Commission on the

Space Shuttle Challenger Accident."
Washington DC, June 1986.

Vaughan, The Challenger Launch Decision

13. An online example:
Union Carbide Bhopal Accident
Causal factors include three protective systems
out of service:

refrigeration system out of service because of operating costs

high temperature alarm was reset high

scrubber inadequately sized for large release, under repair

flare stack out of commission; inlet line under repair
Read MUCH more here: http://is.gd/UCBhopal