Defining IT system: a philosophical exploration

In the world of IT, our primary focus is on designing, building, running, and supporting systems. But when you stop to think about it, what exactly is an "IT system"? Is it defined by its functionality, the technology it uses, or something else entirely? Here are some hopefully not too random ramblings on the topic.

Let’s start with a simple example. Imagine you have a customer relationship management (CRM) system coded in C++. Now, suppose you convert this system into Java without the user noticing any difference—except for the new defects that inevitably crop up. Would you still consider it the same system? I would argue it’s not. But if you only converted a small module to Java, it still feels like the same system.

What if you add new functionality? If it’s related to customer relationship management, I’d say yes, it’s still the same system. However, if you add marketing functionalities, then it starts to feel like a different system.

Consider a more complex scenario: an enterprise resource planning (ERP) system with interconnected subsystems for finance, HR, sales, inventory, and so on. Here, we have systems within systems. The degree of granularity matters—a high-level view might not distinguish between various versions, but a detailed perspective might see each version as a separate system, much like Borges' character, Funes, who perceives each evolving form of a cloud as a distinct cloud.

This phenomenon raises a question similar to when a mound becomes a hill, and a hill becomes a mountain. It also parallels the philosophical thought experiment of the Ship of Theseus, where a ship has all its decaying parts replaced with new timber over time. Is it still the same ship? Similarly, human bodies renew most of their cells over time, and our personalities evolve—what defines our identity?

So, are there objective criteria for what constitutes an IT system, or is it merely a social construct? Perhaps an IT system is simply what we collectively agree it to be. Or is that a cheap post-modernist get-out-of-jail card, avoiding the need for concrete definitions?

Note: Funes the Memorious is a short story by Argentine writer Jorge Luis Borges. It tells the tale of Ireneo Funes, who, after a horseback riding accident, acquires the remarkable ability—or curse—of remembering absolutely everything.