If you try to look up the phrase run to ground in an online dictionary, you get definitions that boil down to “to find a person after a long, difficult search.” It is usually applied to fugitives or people who are otherwise trying to elude capture. Some sources say that the phrase originated in fox hunting, where the hunters chased a fox until it became exhausted.

But that’s not what it means at Microsoft.

Let’s see if we can figure it out from citations.

Here’s an example from sales:

The customer said that they have been identifying more and more scenarios where the data analysis product would be useful. However, they haven’t run to ground the use of XYZ data in their data science team.

So it sounds like they are interested in the product, but there’s some issue about how they use XYZ data that needs to be “run to ground”, which sounds like it’s an important step in resolving that issue.

Here’s an example from a planning meeting:

It will take about a month to run to ground the new scenarios, and until then, engineering is going to focus on reliability of existing features.

And here’s an excerpt from a justification for why a document was not approved:

Hi, there are some risks and gaps that will need to be addressed before we proceed. We have many opens that will need to be run to ground on this.

And here’s a citation from a discussion of how a feature should be designed:

The preferred path would be to do X. Team Y initially ruled out that plan due to reliability concerns, but Bob is engaging with Carol from Team Y to run that to ground.

It seems that the phrase run to ground means roughly “resolve a complex issue.”