Paid for software usually comes in two flavours: turnkey or with consultants. In both cases the promise is that the software will in the end run, and those who need to will actually be able to use it. Also, that the software does something that should be useful to you.
Open source software comes "AS IS", WITHOUT WARRANTY OF ANY KIND. So, who is promising that the software will run, that people will be able to use it and that it does something actually useful to the large enterprise?
If the enterprise has never used that software, long time employees have usually no professional experience with it, so it is risky have them install and run it.
In my limited experience, adoption of open source software by large enterprises comes most of the times through consultants, hired not to install the software but to solve a business problem. The consultants promise to solve the problem with the software, and that the software will run etc.
> Open source software comes "AS IS", WITHOUT WARRANTY OF ANY KIND.
As far as I'm aware, most proprietary licenses have the same disclaimer. Have you ever seen Oracle getting sued when their database segfaults and loses data (in a similar way that a contractor would get sued for building a bridge that crashes)? You usually pay for support contracts with big enterprises, which have external guarantees and experts on call. Luckily, free software companies provide the same services without taking the freedom from the users of that software.
I'm not talking of the proprietary license, but of the exchange between buyer and seller. I've never talked to an Oracle salesperson, but I doubt that they'd say that the software isn't guaranteed to run and/or be useful.
The same goes for FOSS when a consulting company is involved: they say that the software will work; my point is that that's the most likely way in which a large enterprise can run FOSS.
There are other ways, of course: the decision can come from a high enough manager (or even from the CEO or CTO) who's willing to take the risk, but, indeed, they are taking a risk.
Open source software comes "AS IS", WITHOUT WARRANTY OF ANY KIND. So, who is promising that the software will run, that people will be able to use it and that it does something actually useful to the large enterprise?
If the enterprise has never used that software, long time employees have usually no professional experience with it, so it is risky have them install and run it.
In my limited experience, adoption of open source software by large enterprises comes most of the times through consultants, hired not to install the software but to solve a business problem. The consultants promise to solve the problem with the software, and that the software will run etc.