The following reasons have been given for the failure of computerized systems:

a. A system designed for one purpose was used for another purpose.

b. Software was reused without adequate testing.

c. There was an error in storing or converting a data value.

d. A line of code became a single point of failure.

e. The overall system was too complicated to analyze.

f. There was a software race condition.

g. There was another software error (other than those listed in a–f).

For each of the following systems, select the principal reason or reasons why it failed to operate as specified.

• Patriot missile

• Ariane 5

• AT&T long-distance network

• Mars Climate Orbiter

• Mars Polar Lander

• Denver International Airport baggage system

• Tokyo Stock Exchange

• Direct-recording electronic voting machines

• Therac-25