Simulation Differences

IT Asset Management (Cloud)

The license calculations performed during a simulation are likely to match closely to the actual license calculations resulting from a full license reconciliation of your entire enterprise. However, there are several factors that may lead to differences between these counts.

IBM PVU Sub-Capacity Calculations

IBM accepts sub-capacity calculations by its own tools (like ILMT), or by IT Asset Management suitably configured for higher frequency hardware scans (for details, see IBM High-Frequency Scanning). However, the ILMT data is imported as a set of fixed results, which limits ability to simulate changes.

Therefore the calculations made during a simulation for IBM PVU licenses operate as follows:

  • Only IT Asset Management calculations are used
  • Simulation takes into account the setting in the License calculation uses host capacity field on the Use rights & rules tab of the license properties. That is, if this is field is checked, full capacity licensing is used. Otherwise, sub-capacity licensing is used.
  • Simulation does not take into account the setting in the Allow sub-capacity licensing for sources other than ... field on the Use rights & rules tab of the license properties.

The results for simulations of IBM PVU license consumption are likely to match sub-capacity calculations taken from ILMT under matching circumstances.

Scoping Is Respected

Compliance calculations in the IT Asset Management console cover the entire enterprise. When you create a simulation, the data restrictions applying to your access rights are honored. This may mean that your simulation results are incomplete in these two dimensions:

  • Hardware — If computers (as assets) are assigned to particular enterprise groups, and you do not have rights to see data for those groups, those computers are excluded from your simulation. You can simulate changes only to that subset of all hardware that you are entitled to see.
  • Licenses — Similarly, if licenses are assigned to particular enterprise groups, and you do not have rights to see data for those groups, those licenses are excluded from your simulation. Your simulation can only include applications linked to licenses that you are entitled to see.

With these restrictions, simulations are valid for your authorized context, but the numbers may differ from compliance calculations that cover the entire enterprise.

Simulated License Choices Are Fixed

In real compliance calculations displayed in the web interface, an application that is linked to more than one license consumes from one or the other based on complex circumstances (for example, license priorities, whether one license is already fully consumed, upgrade/downgrade rights, and so on). From one compliance calculation to the next, changed circumstances may mean that a given installation consumes from a different license.

In a simulation, licenses are linked to software installations in one of these ways:

  • If the software installation and its associated license were part of the original snapshot that started the simulation, the link was created in the prior compliance calculation and captured in the snapshot.
  • If you create a new simulated software installation, you nominate its linked license at the time you create it.

In both these cases, the link between software and license never changes in a simulation (in contrast to real compliance calculations). You may move the software around, and its linked license moves with it, recalculating points consumption for each new environment.

If it happens that you want to simulate allocation of a different license to a software installation on a particular computer, you can delete the first software installation, and create another copy of the same software on the same computer, but linked at creation time with the alternative license.