Know every application you run — or pay for it twice
You can't manage what you can't see. If no one can list the applications your organisation runs — the ones you built and the ones you bought — then you don't really know what capabilities you have. And what you can't see, you buy again.
The cost of not knowing
Without a single view of your applications, the same capability gets purchased twice — two tools doing the same job, each with its own licence, contract, and bill. Meanwhile, applications nobody catalogued keep running quietly until something breaks and no one is quite sure what it was or who owns it.
Keep the catalogue where service management lives
The natural home for that catalogue is the same system as your IT service management. Put it there and each application connects to the things that matter: the infrastructure it runs on, the agreements and SLAs behind it, and the team that supports it. Support gets easier, keeping the application healthy gets easier — and operations are far happier when they aren't asked to fix an application they never knew existed.
Make purchasing part of it
Fold the purchasing process into the same flow. That gives you vendor vetting, real management of agreements, and buying at the right price — and it keeps a non-serious vendor from talking you into something you'll regret. A purchase then starts as a requirement checked against what you already own, not an impulse buy of something that looked nice.
Security and compliance follow
A complete, connected catalogue is also a gift to your information security officers. When every application, the data it holds, and the contracts behind it are visible in one place, it is far easier to make sure data isn't leaking where it shouldn't — and to show that you meet your compliance obligations.
It comes back to one discipline: know what you have, buy against a real requirement, and keep it all where the rest of your operations can see it.