Can We Trust the Computers?

 What Can Go Wrong?

Q: How do we distinguish between tolerable or unavoidable errors in software versus careless software development?

•Facts About Computer Errors

•Error-free software is not possible.

•Most computer applications, from consumer software to systems that control airplanes and telephone networks, are so complex that it is virtually impossible to produce a program with no errors.

•Are computer-controlled medical devices, factory automation systems, and airplanes too unsafe to use?

•Errors are often caused by more than one factor.

•Errors can be reduced by following good procedures and professional practices.

•The Roles of People in Computer-related Problems:

–Computer User

•At home or work, users should understand the limitations of computers and the need for proper training and responsible use.

–Computer Professional

•Understanding the source and consequences of computer failures is valuable when buying, developing, or managing a complex system.

–Educated Member of Society

•Personal decisions and political, social, and ethical decisions depend on understanding computer risks.

Q: Describe a computer error or failure that has affected you.

•Problems for Individuals

–Billing Errors

•Lack of tests for inconsistencies and inappropriate amounts.

–Database Accuracy Problems

•Incorrect information resulting in wrongful treatment or acts.

–Causes:

•Large population.

•Human common sense not part of automated processing.

•Overconfidence in the accuracy of data from a computer.

•Errors in data entry.

•Information not updated or corrected.

•Lack of accountability for errors.