Even if the code is 100% correct, the usability of the system depends on its performance. If the system is too slow or inefficient, consumers will abandon it unless they are forced to use it. Such a monopoly is rare in the world of commercial software.
To illustrate this point, we can provide some statistics based on consumer-facing web applications. For modern web applications, some polls show that 47% of the consumers expect the page to load in under 2 seconds, and abandon the site if it takes more than 3 seconds to load. As technology improves, user expectations only get higher.
The following chart illustrates the web page abandonment rate as a function of the page load time.
The following two metrics need to be assessed to ...