Chapter 8 Errors, Failures, & Risks

Real Headlines Navigation system directs car into river Data entry typo mutes millions of U.S. pagers Flaws found in software that tracks nuclear materials IRS computer sends bill for $68 billion in penalties Robot kills worker California junks $100 million child support system Man arrested 5 times due to faulty FBI computer data

Problems for Individuals Billing errors – Page 407 Inaccurate or misinterpreted data in databases Physical problems – Blackberry Thumb and RSI

System Failures Phone systems Travel systems – Amtrak, airlines Mars Climate Orbiter Test results in NY Other systems

Computers in the Air “Fly-by-wire” airplanes Other airline examples in book

What would you do? Your team is working on a computer-controlled device for treating cancerous tumors. The computer controls direction, intensity, & timing of a beam that destroys the tumor. Various delays have put the project behind schedule, and the deadline is approaching. There will not be time to complete all the planned testing. The system has been functioning properly in the routine treatment scenarios tested so far. You are the project manager, and you are considering whether to deliver the system on time, while continuing testing, and to make patches if the team finds bugs.

Therac-25 SW controlled radiation therapy machine to treat people with cancer , Therac-25 machines at 4 medical centers gave massive overdoses of radiation to 6 patients – 3 patients died