One of the most expensive moves IBM makes in an audit is denying a sub-capacity claim and defaulting the deployment to full-capacity charging. The cost difference is not marginal. A WebSphere instance using four of a host's thirty two cores is 480 PVU under sub-capacity and 3,840 PVU at full-capacity, an eight fold swing on a single product. The good news for buyers: a denial built on a tooling technicality can often be reversed with the right evidence.
Why IBM denies sub-capacity.
Sub-capacity licensing lets you license only the virtual cores running IBM software rather than the whole physical host, but it comes with conditions. IBM defaults to full-capacity when it concludes that any of the following failed: ILMT, or an approved tool such as Flexera One ITAM or HCL BigFix Inventory, was not deployed within ninety days of first eligible deployment; it did not run continuously; or quarterly reports were not generated and retained for two years. A denial usually rests on one of these points, not on the actual capacity you ran.
The evidence that reverses it.
Reversing the denial means proving the sub-capacity conditions were in fact met for the period in question, or that the gap was narrower than IBM assumed. The evidence that carries weight includes:
- Continuous scan history showing the tool was operating across the disputed period, not just at a single point in time.
- Retained quarterly sub-capacity reports covering the lookback, demonstrating the reporting obligation was satisfied.
- Deployment dates establishing that tooling was in place within the ninety day window for each eligible product.
- Corrected software classification where ILMT miscategorized an install and inflated the count, with the manual correction documented.
Narrowing the period even when there is a gap.
Not every denial can be fully reversed, but few should be accepted whole. Where a genuine gap exists, the goal shifts to confining full-capacity charging to the exact window the evidence cannot cover, rather than letting IBM apply it across the entire lookback. A gap of one quarter is not a license to charge full-capacity for five years. Precise dates and clean scan history turn a sweeping default into a contained, far smaller exposure.
A sub-capacity denial is a claim, not a verdict. The buyer side response is to meet it with the ILMT record line by line: continuous operation, retained quarterly reports, deployment dates and corrected classifications. In a representative manufacturing matter, a methodology challenge backed by clean ILMT evidence cut the claim by 71 percent. The math only works if you preserve the data before IBM asks for it.
Building the reversal into the settlement.
Once the evidence is assembled, the reversal becomes a negotiation. The findings are challenged item by item, the incorrect full-capacity assumption is disputed with the scan record, and the corrected position is written into the settlement. Done well, the same evidence that reverses the historical denial also supports a reinstatement plan so the sub-capacity right is secure going forward.