Why does the performance of an application mean so much to so many?

Regardless of the industry, a decrease in the performance or quality of a software system can mean big losses. Software systems today control our finances and control the machines that take care of our health or our public transportation. There is almost no area in our lives that is not at least partially computerized. Not only losses: in a globalized and competitive world, a company producing low-performance software will soon be devoured by the more efficient and cheaper competition.

For a while, the only metric used in software development was "Is the software correct? Is it doing what it is supposed to be doing?". This made sense at the dawn of the computer systems era, when not every single process was computerized and we had not developed a culture of software engineering or good methods for quality control, team organization, and so on. Now, everybody demands more.

Graphs are an excellent way to display information. Let's analyze the smartphone penetration numbers:

The numbers are clear. In the last quarter of 2008, in almost every region of the world smartphone penetration was under 20%. Nowadays, in 2015, most developed countries present a penetration close to 80%, whereas developing countries are close to 40%. In 2020, it is estimated that developed countries will have a penetration close to 100%, and countries in development over 50%. There are a few countries with more mobile phones than inhabitants!

Mobile users nowadays do not only check their e-mail on a mobile phone. There are many operations that are performed on a mobile phone: the entertainment industry, banking and payment, tourism and traveling, gaming… This leads us to a conclusion: software must be not only correct but also efficient. Failure in software will lead to annoyed customers who might opt to use a different competitor with a better-performing product. In extreme cases, non-performing software can lead our business to lose its revenue—imagine the case of an application to make hotel reservations where you cannot proceed to payment.