Tags with keywords in SharePoint

I know much about SharePoint metadata already. Also about the term store and the content type hub, where I can assign content types to many SharePoint pages.

What I don't know is a smart way how to implement tagging.

My scenario looks like this:

1. We have many SharePoint pages for our customer projects, each one for a machine we sold to a customer.

2. Sometimes failures in our customer projects happen. Those failures are repeating through many of our projects.

3. Each failure has a name

4. A failure can be described with different keywords in different languages. For example:

1. Name: Ram broke down

Search terms: Ram break, Ram failure, Hopper leackage, Stempel fehlerhaft, ...

2. Name: Oil too hot

Search terms: Oil issue, Öl zu heiß, Öl boiling

3. Name: Pressure too high

Search terms: Pressure problem, Druck zu hoch, ...

If a failure happens, people should be able to assign the Name of the failure to a set of files (a document set, a library or something similar)

If other people search later for specific search terms, the cases should be found.

For example:

In ten different SharePoint pages I assigned the "Ram broke down" failure to a set of documents.

If people are now searching for "ram failure", they should find all ten SharePoint pages, because "ram failure" is a search term for the failure "Ram broke down".

However, with normal metadata something like this cannot be archived.

One idea would be to use a managed metadata field for each failure and store all search terms below it. 

But assigning those to documents will be tedious, because all "search terms" have to be added manually.

There must be a better idea... 
Do you have any alternative solution?