Edit 2023-01-08 - this blog post was initially published on https://www.unic.com/en/competencies/experts-blog/2017/effective-it-strategy but deleted - I copied here for future reference:
One of the key challenges in IT is that not every system is created equal. When developing services we try to harmonize the way we manage IT systems and the applications provided by them. However, we see an increasing tension between flexibility and reliability. Very generally we want agility when it comes to systems that allow us to work and collaborate in new ways. On the other hand, we could not get things done if all systems were in constant flux. So we aim for stability for systems that provide standardized services.