Episode 1 The first version of the software is implemented.
Episode 2 Test show that the required constraint of an average response time of 1 second
for deciding on the validity of a dollar bill is not achieved. In fact, on average, it takes 10
seconds to get a response. Senior management discovers the cause. It seems that, to get
the required 98 percent accuracy, a programmer has been instructed by her manager to use
double-precision numbers for all mathematical calculations. As a result, every operation
takes at least twice as long as it would with the usual single-precision numbers. The result is
that the program is much slower than it should be, resulting in the long response time.
Calculations then show that, despite what the manager told the programmer, the stipulated
98 percent accuracy can be attained even if single-precision numbers are used. The
programmer starts to make the necessary changes to the implementation.