① Explainer · Licensing concept
The entry rung of IBM's pricing ladder. A flat, full capacity charge on the smallest z machines, with no sub-capacity break and a sharp cost cliff the moment you outgrow it. Here is when it helps you, and exactly where it turns against you.
zELC buys you simplicity at the bottom of the range. The bill is fixed, predictable, and completely blind to how little of the machine you actually use.
zSeries Entry License Charge (zELC) is an IBM Monthly License Charge metric for the smallest, entry capacity z machines. It is a full capacity charge: software is priced on the rated capacity of the entry processor rather than on measured consumption, and it is offered as a flat price for that specific entry model. IBM introduced it for entry servers such as the z800, and applied it to the entry capacity settings of later machines like the z890, z9 BC, and z10 BC. There is no rolling four hour average and no SCRT report in play.
That is the deliberate trade. On the smallest boxes, the administrative overhead of sub-capacity measurement is not worth the savings, so IBM offers a flat entry charge instead. The catch is structural: zELC only applies to the entry rung. Climb off it, through a hardware refresh or a capacity increase, and the product transitions to a sub-capacity capable metric such as AEWLC or AWLC, with a different and usually higher bill. The danger with zELC is never the entry price. It is the cliff at the edge of it.
zELC is one rung on IBM's MLC ladder. Each rung changes both the metric and how the bill is computed. This is the structural map, not a price list. The figures are illustrative MSU bands, not quotes.
| Rung | Typical machine class | Charge basis | Sub-capacity break |
|---|---|---|---|
| zELC | Smallest entry models, entry setting | Flat, full rated capacity | No |
| EWLC / AEWLC | Mid entry machines | Per MSU, measured | Yes |
| AWLC | Full size machines | Per MSU, measured, tiered | Yes |
| Tailored Fit Pricing | Modern z, consumption model | Annual baseline plus growth | N/A |
Read the ladder top to bottom as your estate grows. The jump out of zELC into AEWLC or AWLC is the one that surprises buyers, because the entry charge was flat and predictable, and the metric it lands on is neither. Exact metric eligibility depends on the specific machine and IBM's current terms.
zELC bites in two directions. While you are on it, you cannot use sub-capacity levers to lower the bill, because there is no consumption measurement to manage. And when you leave it, the metric change can step your software cost up faster than the hardware upgrade that triggered it. Both are predictable, which means both are negotiable if you model them before the decision rather than after the invoice. The decision tree below is how we frame it.
| If | Then | Watch for |
|---|---|---|
| Capacity is stable at the entry setting | zELC flat charge is usually the simplest, lowest entry cost | Idle products still on the bill |
| A hardware refresh is on the horizon | Model the AEWLC or AWLC charge before ordering the box | The metric cliff at the upgrade |
| Consumption is well below capacity | A sub-capacity metric may already beat the flat charge | Whether the machine even qualifies |
| The estate is shrinking or consolidating | Retire products and revisit metric eligibility together | Stranded licenses on a downsized box |
Metric eligibility and pricing behavior depend on the machine, the capacity setting, and IBM's current terms. These are patterns we commonly observe on entry estates, not guarantees for any one configuration.
zELC is the entry point of the same ladder that runs through EWLC and entry workload license charges and up into AWLC, advanced workload license charges, and the whole sequence is traced in IBM Z software pricing history from PSLC to TFP. Because it is a full capacity charge, it is the opposite end of the spectrum from sub-capacity versus full capacity licensing, and the metric jump it triggers is exactly the kind of event covered in hardware refresh and software cost. When a refresh or a metric change is on the table, that is the work on mainframe cost optimization.
Audit notice or renewal under 18 months out? We mobilize within 48 hours. Facing the metric cliff out of zELC on your next refresh? Start here.
zSeries Entry License Charge (zELC) is an IBM Monthly License Charge metric for the smallest, entry capacity z machines. It is a full capacity charge: software is priced on the rated capacity of the entry processor, not on measured consumption, and it is offered as a flat price for that specific entry model. It was introduced for entry servers such as the z800, and entry settings on the z890, z9 BC, and z10 BC.
No. zELC is a full capacity metric. There is no rolling four hour average, no SCRT report, and no sub-capacity break. You pay the entry charge for the entire rated capacity of the machine regardless of how little of it you use. That is the trade off: a simple, predictable, low entry price in exchange for losing the consumption based savings that sub-capacity metrics like AEWLC and AWLC provide.
When you outgrow the entry model. zELC only applies to the entry capacity setting of an entry class machine. The moment a hardware upgrade or capacity increase moves you off that entry point, the product transitions to a sub-capacity capable metric such as AEWLC or AWLC, and your software charge can step up sharply. That transition is a cliff, not a slope, and it should be modeled before the hardware decision is made, not after.
They are points on the same pricing ladder. zELC is the flat entry rung for the smallest machines. EWLC and its successor AEWLC are the sub-capacity metrics for mid entry machines. AWLC is the sub-capacity metric for full size machines. As your capacity grows you climb the ladder, and each step changes both the metric and the way your bill is calculated. Knowing which rung you are on, and what the next one costs, is the whole game on small estates.