Why Software reliability is more important than efficiency?

Answer 1

Reliability should always take precedence over efficiency for the following reasons:

1. Computers are now cheap and fast: There is little need to maximize equipment usage. Paradoxically, however, faster equipment leads to increasing expectations on the part of the user so efficiency considerations cannot be completely ignored.

2. Unreliable software is liable to be discarded by users: If a company attains a reputation for unreliability because of single unreliable product, it is likely to affect future sales of all of that company's products.

3. System failure costs may be enormous: For some applications, such a reactor control system or an aircraft navigation system, the cost of system failure is orders of magnitude greater than the cost of the control system.

4. Unreliable systems are difficult to improve: It is usually possible to tune an inefficient system because most execution time is spent in small program sections. An unreliable system is more difficult to improve as unreliability tends to be distributed throughout the system.

5. Inefficiency is predictable: Programs take a long time to execute and users can adjust their work to take this into account. Unreliability, by contrast, usually surprises the user. Software that is unreliable can have hidden errors which can violate system and user data without warning and whose consequences are not immediately obvious. For example, a fault in a CAD program used to design aircraft might not be discovered until several plane crashers occurs.

6. Unreliable systems may cause information loss:Information is very expensive to collect and maintains; it may sometimes be worth more than the computer system on which it is processed. A great deal of effort and money is spent duplicating valuable data to guard against data corruption caused by unreliable software. Software failure costs often far exceed system costs.