One nice thing about being in Enterprise Architecture: you get to watch as the infrastructure changes. When you are working on one big project or another, or even a dozen different projects over the course of the year, you only see the changes that you helped to create, but in EA, we have to take a regular inventory. It is then when you realize all the things that have actually happened the year before.
And it is then that you sometimes find that the data about your application portfolio doesn't match reality.
In our area, we had a small exercise last fall where we were classifying the applications according to whether they were Strategic, Core, Maintain, or Sunset. It's a part of Application Portfolio Management called Application Segmentation.
The practice allows the organization to inspect the investments across the portfolio (Project Portfolio Management) to see how many of the investments, or how much of the money, is going towards strategic needs vs. core needs vs. maintenance, etc. You could even make portfolio decisions, like "of our total budget, we want to spend X% on strategic needs" which could move a few of the projects into, or out of, the Plan of Record (POR).
Anyway, while doing this exercise, one of my friends in a different group noticed that one of the "apps" in the portfolio wasn't really an app at all. The PM who had created the entry had been working on a project and thought that "all projects need their own application id" so he created one, even though the project didn't create a new app... it modified one.
So my friend did the rational thing: he asked that the 'entry' be removed. Our support manager agreed and the application entry was removed. Unfortunately, I wasn't aware of this.
Now, the end of the year rolls around, and I'm taking my annual inventory and updating models, and I notice that the app is marked as 'retired.' I know that the functionality is still there. Few people remember why the app was 'turned off' and my friend's name is not on the entry's log anywhere. It took about an hour to figure out what was going on. Once I realized what he had asked for, I agreed with the logic and removed the entries from my models.
Point being: Enterprise Architecture is intimately tied to Application Portfolio Management as well as Project Portfolio Management. Make sure that your processes for review and governance include process points when an application is decommissioned, not just when it is rolled out. Otherwise, you, too, will spend a few hours, at some later date, trying to track down "what the heck happened to the SNAFU app?"