How are Flexible Use licenses dynamically allocated and shared among several users? Most application programs acquire a license as soon as they are started, and release the license when they are finally closed. But because the Premium Solver and Risk Solver products work inside Microsoft Excel, they behave differently -- for your benefit.
Although our Solver software is loaded and briefly used every time you start Excel (if the relevant box is checked under COM Add-ins), the Solver does not acquire a Flexible Use license at this time. You can start Excel and use it for other purposes without using a Solver license at all.
When you select our Ribbon tab in Excel 2007, or use Tools Solver... in Excel 2003, the Solver acquires a license (to verify that you have one) and then immediately releases it. You are now able to use the Solver interactively for as long as you want, but the license server will "hold" a license available solely for your use, for a maximum of ten minutes -- during this time you can reacquire this license, but no one else can. After ten minutes, any user can acquire the license that you were using.
When you click the Simulate, Optimize or Check Model button, the Solver again acquires a license, and releases this license as soon as the operation finishes. You can then inspect the results, and continue to use the Solver interactively for as long as you want, but your Flexible Use license is "held" available solely for your use, for a maximum of ten minutes after the operation finishes.
Note that all users who have ever acquired a Flexible Use license since they started their current Excel session can continue to use the Solver's interactive features, for as long as they like, without tying up a license. The ten minute "quantum" applies when they first select the Solver, and then whenever they choose Simulate, Optimize or Check Model.
What would happen if the Flexible Use license was not held for your use for ten minutes? After selecting the Solver and working interactively for a while, you are very likely to click Simulate, Optimize or Check Model, probably within ten minutes. Users also frequently perform these operations, inspect the results, and then perform them again within a few seconds or minutes. But if your license was not held, it could easily be lost during this time, if another user acquired it from the server, and you would not be able to proceed with your work. The ten minute quantum or "hold time" is designed to be long enough to enable you to keep working without frequent interruption, but short enough to permit Flexible Use licenses to be effectively shared among several users.
If you have questions about Flexible Use licenses, please contact us!