IBM Mainframe: Workload License Charges (WLC) Pros & Cons

It is estimated that less than half of eligible IBM Mainframe customers deploy the VWLC pricing mechanism, which in theory, is the lowest cost IBM software pricing metric.  Why?  In the first instance, let’s review the terminology…

Workload License Charges (WLC) is a monthly software license pricing metric applicable to IBM System z servers running z/OS or z/TPF in z/Architecture (64-bit) mode.  The fundamental ethos of WLC is a “pay for what you use” mechanism, allowing a lower cost of incremental growth and the potential to manage software cost by managing associated workload utilization.

WLC charges are either VWLC (Variable) or FWLC (Flat).  Not all IBM Mainframe software products are classified as VWLC eligible, but the major software is, including z/OS, CICS, DB2, IMS and WebSphere MQ, where these products are the most expensive, per MSU.  What IBM consider to be legacy products, are classified as FWLC.  More recently a modification to the VWLC mechanism was announced, namely AWLC (Advanced), strictly aligned with the latest generation of zSeries servers, namely zEC12, z196 and z114.  For the smaller user, the EWLC (Entry) mechanism applies, where AEWLC would apply for the z114 server.  There is a granular cost structure based on MSU (CPU) capacity that applies to VWLC and associated pricing mechanisms:

Band MSU Range
Base 0-3 MSU
Level 0 4-45 MSU
Level 1 46-175 MSU
Level 2 176-315 MSU
Level 3 316-575 MSU
Level 4 576-875 MSU
Level 5 876-1315 MSU
Level 6 1316-1975 MSU
Level 7 1976+ MSU

Put simply, as the MSU band increases, the related cost per MSU decreases.

IBM Mainframe users can further implement cost control by specifying how much MSU resource they use by deploying Sub-Capacity and Soft Capping techniques.  Defined Capacity (DC) allows the sizing of an LPAR in MSU, and so said LPAR will not exceed this MSU amount.  Group Capacity Limit (GCL) extends the Defined Capacity principle for a single LPAR to a group of LPARs, and so allowing MSU resource to be shared accordingly.  A potential downside of GCL is that is one LPAR of the group can consume all available MSU due to a rogue transaction (E.g. loop).

Sub-Capacity software charges are based upon LPAR hardware utilization, where the product runs, measured in hourly intervals.  To smooth out isolated usage peaks, a Rolling 4-Hour Average (R4HA) is calculated for each LPAR combination, and so software charges are based on the Monthly R4HA peak of appropriate LPAR combinations (I.E. where the software product runs) and not based on individual product measurement.

Once a Defined Capacity LPAR is deployed, this informs WLM (Workload Manager) to monitor the R4HA utilization of that LPAR.  If the LPAR R4HA utilization is less than the Defined Capacity, nothing happens.  If the LPAR R4HA utilization exceeds the Defined Capacity, then WLM signals to PR/SM and requests that Soft Capping be initiated, constraining the LPAR workload to the Defined Capacity level.

If a user chooses a Sub-Capacity WLC pricing mechanism, they will be required by IBM to submit a monthly Sub-Capacity Reporting Tool (SCRT) report.  Monthly WLC invoices are based upon hourly utilization metrics of LPAR hardware utilization, where the software product executes.  The cumulative R4HA and bottom line WLC billing metric is calculated for each product and associated LPAR group and not based on individual product measurement.

Bottom Line: From a Soft Capping viewpoint, the customer only pays for WLC software based upon the Defined Capacity (DC) or Rolling 4-Hour Average (R4HA), whichever is the lowest.  So whether a customer uses Soft Capping or not, in all likelihood, there will be occasions when their workload R4HA is lower than their zSeries server MSU capacity.

So, at first glance, VWLC seems to provide a compelling pricing metric, based upon Sub-Capacity and a pay for what you use ethos, and so why wouldn’t an IBM Mainframe user deploy this pricing metric?

The IBM Planning for Sub-Capacity Pricing (SA22-7999-0n) manual states “For IBM System z10 BC and System z9 BC environments, and z890 servers, EWLC pricing is the default for z/OS systems, and Sub-Capacity pricing is always the best option.  For IBM zEnterprise 114, environments, AEWLC pricing is the default for z/OS systems, and Sub-Capacity pricing is always the best option.  For IBM zEnterprise 196, System z10 EC and System z9 EC environments, and other zSeries servers, Sub-Capacity pricing is cost-effective for many, but not all, customers.  You might even find that Sub-Capacity pricing is cost effective for some of your CPCs, but not others (although if you want pricing aggregation, you must always use the same pricing for all the CPCs in the same sysplex)”.

Conclusion: For all small Mainframe users qualifying for the EWLC (AEWLC) pricing metric, arguably this pricing mechanism is mandatory.  For the majority of larger Mainframe users, the same applies, although a granularity of adoption might be required.  IBM also have a disclaimer “Once you decide to use Sub-Capacity pricing for a specific operating system family, you cannot return to the alternative pricing methods for that operating system family on that CPC.  For example, once you select WLC you may not switch back to PSLC without prior IBM approval”.  However, the requisite contractual exit clause option does exist; the customer can switch back to the PSLC pricing metric.

Some IBM Mainframe users might object to a notion of Soft Capping, relying upon their tried and tested methodology of LPAR management via the number of CPs allocated and associated PR/SM Weight.  This is seemingly a valid notion and requirement, prioritizing performance ahead of cost optimization.

Conclusion: As previously indicated, with VWLC, SCRT invoices are generated upon a premise of the customer only pays for WLC software based upon the Defined Capacity (DC) or Rolling 4-Hour Average (R4HA), whichever is the lowest.  So the VWLC pricing mechanism should deliver a granularity of cost savings, typically higher for a Soft Capping environment.

Some IBM Mainframe users might just believe that nothing can match their Parallel Sysplex Licensing Charge (PSLC) mechanism, first available in the late 1990’s, which might be attributable to other 3rd party ISV’s who cannot and will not allow for their software to be priced on a Sub-Capacity basis.  In reality, adopting the VWLC pricing mechanism delivers ~5% cost savings when compared with PSLC, as indicated by the IBM Planning for Sub-Capacity Pricing Manual (SA22-7999-0n) and related Sub-Capacity Planning Tool (SCPT).

Conclusion: Adopting Sub-Capacity based pricing metrics can only be a good thing.  If your 3rd party ISV supplier doesn’t recognise Sub-Capacity pricing, whether MIPS or MSU based, perhaps you should consider your relationship with them.  Regardless, the z10 server was the last IBM Mainframe to incorporate the “Technology Dividend” solely based on faster CPU chips.  The lower cost WLC pricing metric is now only available with the AWLC and related (E.g. AEWLC) pricing metrics, as per the z196, z114 and zEC12 servers.

Some customers might state that there is a lack of function or granularity of policy definition for IBM supplied Soft Capping (E.g. DC, GCL) or Workload Management (WLM) techniques.  To some extent this is a valid argument, but wasn’t it forever thus with IBM function?  Sub-Capacity implementation is possible via IBM, as is Workload Management (WLM), Soft Capping or not, but should the customer require extra functionality, 3rd party software solutions are available.

The zDynaCap software solution from zIT Consulting delivers a “Capacity Balancing” mechanism, integrating with R4HA and WLM methodologies, but constantly monitoring MSU usage to determine whether CPU resource can be reallocated to Mission & Time Critical workloads, based upon granular customer policies.  The only guarantee in a multiple LPAR environment, for a Mission & Time Critical LPAR to receive all available MSU resource, Soft Capping or not, is to inactivate all other LPARs!  Clearly this is not an acceptable policy for any installation, and so a best endeavours policy applies for PR/SM DC, GCL and Weight settings.

Conclusion: z/OS workloads change constantly, whether the time of day (E.g. On-Line, Batch) or period of the year (E.g. Weekly, Monthly, Quarterly, Yearly) or just by customer demand (E.g. 24 Hour Transaction Application).  Therefore a dynamic MSU management solution such as zDynaCap is arguably mandatory, implementing the optimum MSU management policy, whether for purely performance reasons, safeguarding the Mission & Time Critical workload isn’t impacted by lower priority workloads, or for cost reasons, optimizing MSU usage for the best possible monthly WLC cost.

In conclusion, not considering and arguably not implementing z/OS VWLC related pricing mechanisms is impractical, because:

  • The VWLC and AWLC related pricing metrics deliver the lowest cost per MSU for eligible z/OS software
  • When compared with PSLC, VWLC related pricing mechanisms deliver conservative ~5% cost savings
  • A pay for what you use and therefore Sub-Capacity pricing mechanism, not the installed MSU capacity
  • If extra MSU policy management granularity is required, consider 3rd party software such as zDynaCap

Software cost savings are not just for the privileged; they’re for everyone!

IBM Mainframe – Enterprise Software License Agreements Pros & Cons

An often quoted phrase in the Mainframe user base is “why are our Mainframe software costs so high”?  Sometimes we might have to look closer to home when finding the answers to our questions…

Over the years, Mainframe software portfolios in the customer environment might have become unwieldy, with duplication of software function, unused software, unsupported software products, and so on.  Typically this scenario occurs due to Merger & Acquisition (M&A) activity, where in an ideal world, a standard LPAR (image) with an optimally configured software portfolio would be deployed, which inevitably will generate the requirement for a modicum of migration activity, from one software product to another.  The complexity of software migration can change dramatically from a simple change, generally associated with Systems Management (E.g. Monitors) products to enormously complex, generally involving Database Subsystems (E.g. Adabas, DB2, IDMS, et al) and Programming Languages (E.g. COBOL, PLI, et al) while there is some middle ground with some Systems Management products (E.g. Security, Storage, Scheduling) that maintain metadata (policy data).  Therefore only the truly committed Mainframe user will adopt and fully commit to this standard LPAR methodology, benefitting to some extent from lower software costs.

Similarly over the last 20 years or so, the perceived requirement for Enterprise Software License Agreements has increased, where the fundamental premise is that such agreements make life easier for both the customer and ISV alike.  An interesting notion indeed, and one must draw one’s own conclusions as to whether such a utopia can exist; therefore as always, the caveat emptor (let the buyer beware) term must apply!

However, with such fully encompassing requirements and associated pricing mechanisms, the need for each and every major ISV to have a fully rounded software portfolio has ensued.  Therefore we have witnessed a lot of M&A activity in the Mainframe ISV market place, where several dominant players have emerged, in no particular order, BMC (Advantage), CA (FlexSelect, MLP, OLP) and IBM (ESSO, ELA), while some might say ASG should be included in this list.  Generally it seems to be the norm that each and every Mainframe customer will have at least one Enterprise Software License Agreement in place, typically with IBM because of the need to deploy the z/OS (z/VM, z/VSE, zLinux) operating system, generally in conjunction one other, whether ASG, BMC or CA.

The advantages of an Enterprise Software License Agreement are primarily:

  • Simplified license management via many products from one supplier
  • A several (3-5) year license agreement, only requiring periodic review and negotiation
  • Perceived cost benefit, with discount based upon volume, both in terms of software and CPU power
  • Perceived deployment benefit, treating Distributed and Mainframe platforms equally
  • Simplified support, as each and every software product should have the same look and feel

However, for a balanced review, we must identify the potential disadvantages, for example:

  • Is each and every software product from this single supplier the best for our business?
  • How do we renegotiate this agreement, because our business requirements have unexpectedly changed?
  • How do we exit this agreement, because our relationship with this supplier has failed?
  • How do we calculate a tangible cost and value for each and every product we deploy?

As always, the devil is in the detail, and although most pros and cons seem fairly innocuous at first glance, the considerations generated regarding contract termination or renegotiation are significant.  For example, if the Mainframe user chooses a 3 year Enterprise Software License Agreement, do they need to decide at least 18 Months before contract expiration that they must migrate to alternative software products, to terminate their relationship with a supplier?  So at first glance, volume discount and simplification look good, but how expensive and disruptive will contract termination be?

In real-life human terms, this is somewhat analogous to Marriage, a long-term relationship between two parties that choose to declare significant commitment to one another, but perhaps, the realm of possibility exists that said relationship will fail, and of course, in the absence of a bulletproof pre-nuptial, complications occur, and exit from the relationship is both financially expensive and disruptive.  Hmmm, so where is the equivalent of a pre-nuptial for the Enterprise Software License Agreement?  In an ideal world, the commercially savvy customer will have planned for such a possibility, but whether they have or have not, the supplier will have been paid for their software, and the customer may not have any choice but to renew or extend their agreement!  So which party is the winner and which one is the loser in such a scenario?  Does one party benefit from a heads we win and tails you lose proposition?

How does the Mainframe customer choose the best software product for their business requirement?  In an ideal world, they document their business requirement, collect information on market place offerings, review pricing options, generate a shortlist of suitable products, and eventually choose the “best-of-breed” product.  How is such a structured and balanced approach possible when deploying the Enterprise Software License Agreement?  The first thought must be cost based, as software has already been paid for, so if there’s a product in the portfolio we could use, we need to use it, whether it’s the best product or not.

If a Mainframe user is using an internal chargeback system for computing use, how can they fairly cost the pricing metric, if they don’t know the price of software products used?  Equally, how can the Mainframe user attempt to identify single product pricing when Enterprise Software License Agreements detail no granularity of pricing information?  Perhaps a modicum of research might help, where some global Government regulations dictate that contract details must be published for public scrutiny.  Therefore ISV Mainframe software list pricing details can be identified, for example, IBM and BMC.

One must draw one’s own conclusions, where some Mainframe customers may perform a structured review of the market place, and even though the technical recommendation might be for a product not covered by an Enterprise Software License Agreement, typically from a smaller ISV, the product chosen is one already paid for, or at least available from the Enterprise Software License Agreement.  This generates several issues, including but not limited to, alienating the smaller ISV community, having used them for expediency, and not delivering the best solution for your business…

So does the self-fulfilling prophecy ensue, where the Mainframe customer questions the cost of Mainframe software, but perhaps implicitly or unknowingly, said Mainframe user has contributed to such an environment, where a limited number Mainframe ISV’s control the Mainframe software market?

Isn’t it somewhat of a paradox that in The UK, the monopolies commission would review the merits of an M&A between two major grocery supermarket or energy supplier companies, and yet whether in The UK or globally, there are several major ISV’s (E.g. ASG, BMC, CA, IBM) dominating the Mainframe software market, primarily via Enterprise Software License Agreements?  Can this really be a good thing for the Mainframe user, limited supplier choice and therefore a lack of healthy competition?

Perhaps it is the responsibility of the Mainframe user to actually choose software impartially, and from time-to-time choose the best product, regardless of ISV.  This might generate a more active market place for software choice, while it was forever thus, the larger ISV is so big that they can easily acquire the smaller ISV who has developed and sold a good product, but at least the Mainframe ISV market place continues to evolve.  In this case, it seems somewhat logical that the Mainframe user is in control of their destiny, but only by safeguarding that their default option is not the Enterprise Software License Agreement.  They encourage an active and impartial ISV software market by dispassionately reviewing the open market and choosing the best Mainframe software product for their business!

Lewis Carroll once said “integrity is doing the right thing, even when no one is watching”!  When was the last time a major ISV declared an open book policy for your business, offering you flexible options to benefit from their Enterprise Software License Agreement, while allowing you to choose a best-of-breed software product, but not from their software portfolio, giving you a discount (credit note) for their software product that didn’t match your business requirement?