Is there a best practice for determining how many floating licenses of a product to buy? I need to purchase Rational Rose for 15 developers, but I'm unsure as to how to determine how many floating licenses that will translate to. Since this is a new project, I do not have usage statistics to help me determine when peak times are, etc. Is the consensus to purchase more than needed, and let the excess lapse at renewal time, or do you take a guess and increase as needed? Thanks!
My thoughts ...
I assume a standard "concurrent user" licensing scheme and that all 15 guys work the same hours. I also assume that 15 is not a reasonable answer.
If you can, survey the manager and developers about what fraction of their time will be spent using the tool. Multiply that fraction times 15 and round up. If you can't, then I would use 50% and make sure everyone knows that this is a WAG. I would negotiate with the company the right to purchase more licenses are the same price for some period of time.
The decision about whether to overbuy or underbuy from there depends on whether there is lockout when all the licenses are consumed and the mechanism for getting more licenses. Generally, I like to err on the side of getting an extra license or two.
1- Make sure you understand the licensing terms around the floating license. Be clear about the license terms. Not every company supports "floating" licenses, even if you are planning on using them that way.
2- Also make sure you know how the licenses are enforced .. license manager server, honor system, some kind of token/dongle, or something else.
3- Make sure all know before the decision is made the cost and mechanisms for the addition of licenses.
4- You may need to enforce discipline around folks leaving the tool running when they aren't using it. If you decide to get three licenses, and two of them are being consumed by guys at lunch, two other folks may be out of luck.
5- Plan for review of the situation 2 or 3 times a year plus during budget season.
It would depend on how that company does their licensing. I would get a sales guy on the phone and talk him into letting you expand when you need to and start out small, say, 5?