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PVU, RVU and VPC Metrics
Journal · May 2026 · 7 minute read

Authorized User Single Install vs Floating User.

Two IBM user metrics sound similar and count completely differently. Authorized User Single Install ties a named person to a single installation. Floating User licenses concurrent access from a shared pool. Confuse them, or count one as though it were the other, and the audit gap is built in before anyone runs a scan. Independent, not affiliated with IBM Corporation.

User based metrics avoid the hardware arithmetic of PVU, but they trade it for a different discipline: knowing exactly who counts and under what rule. Authorized User and Floating User are the two most common user metrics, and the word user in both names hides the fact that they measure different things. One counts named people with access. The other counts how many people use the software at the same time. The license you bought decides which question the auditor asks, and the answer has to match.

Two user metrics, two ways to count.

The simplest way to keep them apart is to ask what the entitlement is attached to. Authorized User attaches to a person. Floating User attaches to simultaneous usage of an installation. That single distinction drives every counting rule that follows, including the single install restriction that makes the Authorized User variant stricter than buyers expect.

Authorized User Single Install, defined.

An Authorized User Single Install license authorizes a specific, named individual to access one particular installation of the program. Two consequences follow that buyers routinely miss:

The single install restriction is the trap. A license that felt generous for one environment does not quietly cover a second copy stood up for test, training or a regional site.

Floating User, defined.

A Floating User license is consumed by concurrent use rather than by named identity. A pool of entitlements is shared, and what matters is the maximum number of users accessing the program at the same time. Fifty occasional users sharing a workload that never exceeds ten simultaneous sessions can, in principle, be served by a smaller floating pool than fifty named Authorized User licenses would require. The measurement is the peak of concurrent access, so the discipline shifts from tracking identities to tracking simultaneous usage.

Where audits find the gap.

Most findings on user metrics come from one of a few mismatches:

What this means under audit

Authorized User counts named people on a single installation, and Floating User counts concurrent usage from a shared pool. The single install restriction is the most common trap, because an Authorized User Single Install entitlement does not stretch across a second deployment. Match each product to its real metric and count the way that metric defines, named identities or concurrent peak, before the auditor does.

Common questions.

Does Authorized User count only active users?
No. Authorized User is a named metric. Every distinct individual with access requires an entitlement, whether or not they are all active at the same time. Concurrency is the Floating User concept, not the Authorized User one.
Can one Authorized User Single Install license cover two installations?
Generally no. The Single Install restriction ties the entitlement to access of one particular installation. The same user accessing a second installation typically needs a second entitlement, which is a frequent source of audit findings.
How is a Floating User pool measured?
By concurrent usage. What matters is the maximum number of users accessing the program at the same time, so the pool must be sized to the true peak of simultaneous access rather than to average or total user counts.
Not sure your user counts match the metric you bought?
We reconcile named and concurrent user positions against entitlements, independently and on your side of the table.
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