Sorry to answer this one so late in the game and so long, but this would actually be very easy to do. Costly, but pretty easy to set up. You'll need to create it yourself though or the business would. As far as I know nothing like this exists in sl, but I could be wrong. You may find someone willing to lend out their land, or business, for such exercises as well. Never hurts to ask.
You need property, a full sim would work very nicely for this, but any size at all would do.I say full sim because you'll have more prims, and be able to set up more areas and you won't have to worry about sharing the sim resources with others. This depends entirely on your needs.
You need a business. For this sort of training I would recommend multiple businesses, or areas. It really can be any kind of business at all. Anything from a retail location, to an office setting, to a janitorial or maintenance job, even a club setting could be beneficial, sky's the limit. You'll need all the stuff that would go with such a business too. For retail location you'dd need stuff to sell which could help lower costs too. For office settings you'll need that stuff. I think you get the hint. With the sort of script masters Sl has you can easily find things that will fit your needs. By that I mean furniture and products and such that will simulate what you need them to.
You need people. By this I do not mean the people you are going to train, I mean people to act. Sure you can hopefully count on regular traffic(ie, experience) but that may not pan out right away. You'll want to hire people on as customers, or whatever ti interract with your employees. You'll want these people to be able to act both nice, and not so nice, to your employees. If your goal is to offer actual simulated training, those experiences will be necessary.
Of your employees you will need to require certain things for certain jobs. You can test their ability to interact verbally(textually I guess) with other employees, their employer and the customers. You can test their ability to spend a certain amount of time in front of a computer-not always an easy task. By giving them tasks every so often that require their full attention you can almost guarantee they'll have to be sitting there to complete them(this is how you sort out those who get up and walk away from those who don't). You can test their ability to multitask or at least handle multiple tasks for the day. Many things you could train for in real life can be done virtually in sl, you just have to get creative. If the business is truly interested in something like this, SL is a viable place for such training. It's just a matter of getting the ideas down, and getting to work on them. Also, like I said, it might be costly at first. Well for some it might, I don't know what sort of finances you're working with. If you don't have much, I'd talk to actual business and property owners and see what they might be able to offer for your needs. You may run into issues with hiring people to work as actors, and retaining them. Many will sign up, not all will stay and plenty of them will suck at their job. So it's hit or miss there. Be prepared for problems.
A group that used to help people with rl social issues used to have something similar here in sl. They had a full sim with all kinds of things for their group members to go to and work their way through their issues, and they used paid actors. They closed up shop a couple years ago though and I don't remember what their name was. I think it just got too costly, wouldn't surprise me.