Why don't big companies keep their computer systems up-to-date?

It only makes matters worse when businesses outsource their software development and maintenance

The Equifax hack, exposing 143 million people’s personal data to unknown cybercriminals starting in March but not made public until mid-September, was entirely avoidable. The company was using out-of-date software with known security weaknesses. But it appears that with Equifax, as with many organizations, those were just the beginning of the problems.

During the past three decades we’ve researched, developed and tested millions of lines of software for many purposes, including national defense and security, telecommunications, financial services, health care and online gaming. Over the years we’ve observed that the technical means