① Licensing concept · Sub-capacity pricing
IBM treats every eligible IBM Z machine in a country as a single Multiplex and charges on one combined peak. For a distributed, growing estate that can lower the bill. For a shrinking one, the one way ratchet is the trap.
All eligible machines in one country, charged as one machine. One peak, not many.
Country Multiplex Pricing, CMP, is an IBM sub-capacity offering that collects all eligible IBM Z machines and sysplexes within a single country and treats them as one machine, a Multiplex, for software charging. It removes the aggregation constraints of earlier methods, where charging followed sysplex boundaries, so workloads can move across machines in the country without the old penalties. Software is then charged on a single combined utilization peak for the whole Multiplex rather than a separate peak per machine.
The mechanics run through SCRT. SCRT V23 R10 or later produces a Multiplex report that combines the sub-capacity peaks of every eligible machine in the country at the same moment, instead of reporting each machine alone. Because peaks on different machines rarely land in the same four hour window, the combined Multiplex peak is commonly lower than the sum of the individual machine peaks. CMP also uses Multi-Version Measurement, which treats all versions of a product as one and removes the Single Version Charging migration deadlines that apply under traditional sub-capacity.
A simplified single product across three eligible machines. The Multiplex peak is the combined utilization at the moment the country wide total is highest, not the sum of each machine's own highest moment. Figures are illustrative to show the mechanic.
| Measure | Machine A | Machine B | Machine C |
|---|---|---|---|
| Each machine's own peak (MSU) | 300 | 260 | 220 |
| Its MSU at the Multiplex peak moment | 300 | 150 | 120 |
| Charging basis | MSU charged | Effect |
|---|---|---|
| Sum of separate machine peaks | 780 | What you would pay charging each machine alone |
| Combined Multiplex peak | 570 | The single country wide peak the three reach together |
| Difference | 210 | The aggregation benefit, because peaks do not coincide |
The three machines each peak at a different time, so the moment the country total is highest, only Machine A is at its own peak. Charging the combined 570 MSU instead of the summed 780 is the whole CMP value proposition. The more distributed and staggered the workload, the larger the gap. An estate whose machines all peak together gains little.
The Multiplex capacity establishes a base. When the Multiplex grows, the base resets higher. A later drop in usage does not pull the established base back down. This is the opposite of the month to month flexibility buyers expect from sub-capacity.
| Period | Multiplex usage (MSU) | Established base | Charged on |
|---|---|---|---|
| Start | 570 | 570 | 570 |
| Growth quarter | 640 | 640 | 640 |
| Later, usage falls | 540 | 640 | 640 |
When usage climbed to 640, the base ratcheted up and stayed. When it later fell to 540, the charge held at the established 640. CMP rewards estates that grow, because the aggregation benefit compounds. It punishes estates that shrink, because the protection a normal sub-capacity month would give does not arrive. Model your two to three year capacity trajectory honestly before entering, because the entry decision is hard to reverse.
The established Multiplex level moves up with growth and does not come back down when usage falls. An estate that signs CMP expecting to consolidate or shrink can lock a floor it then pays for indefinitely.
Aggregation only helps when machine peaks fall at different times. If your workload peaks across the estate at once, the combined Multiplex peak approaches the summed peaks and the savings shrink to little.
Which machines and products qualify for the Multiplex is set by the offering terms, and the boundary matters. A machine left outside, or a product not eligible, changes the math, so the scope must be checked against your actual estate.
Moving to CMP reshapes how the whole country estate is charged and is not casually reversed. The decision belongs with a modeled multi year view, not a single favorable quarter of SCRT data.
Model the trajectory, not the quarter. Growth wins, shrinkage loses.
Treat the CMP decision as a multi year capacity forecast first and a pricing form second. Pull the SCRT data for every eligible machine and test how staggered the peaks really are, because that stagger is the entire benefit. Then forecast two to three years of capacity honestly: if the estate is growing and distributed, the Multiplex aggregation can cut the bill meaningfully; if a consolidation or workload exit is on the roadmap, the one way ratchet can trap you above your real usage. Compare CMP against staying on standard sub-capacity and against Tailored Fit Pricing, since all three answer the same question differently.
Understand the metric underneath first: read the rolling four hour average for how each peak is built and single version charging for the migration deadlines CMP removes. When IBM proposes a Country Multiplex, our mainframe license negotiation team models the trajectory against your own data and our IBM contract review checks the eligibility scope and the ratchet terms before you commit.
An IBM sub-capacity offering that treats all eligible IBM Z machines in one country as a single Multiplex and charges on one combined peak instead of a separate peak per machine, removing the old sysplex aggregation limits.
SCRT V23 R10 or later produces a Multiplex report combining the sub-capacity peaks of all eligible machines at the same moment. Because peaks rarely coincide, the combined figure is commonly lower than the sum of individual peaks.
The Multiplex level is a one way ratchet. It moves up with growth and does not fall back when usage drops. CMP suits growing, distributed estates and can trap shrinking ones above their real usage.
No. CMP uses Multi-Version Measurement, which prices all versions as one at the latest coefficients with no migration deadline. The Single Version Charging windows of traditional sub-capacity do not apply.