Jacky Hofbauer - zCost Management founder - explains about IBM Mainframe charter:
The vWLC (variable Workload Licence Charge) process responds to the Value statement of the Mainframe Charter. This billing method authorizes to pay the licence charge on capacity usage, not on “full capacity”.This allows the customer to feel good about controlling his cost. zCOST takes an active role in this charter because the mainframe community ecosystem is strong and growing with a continued investment and increased availability of skills: zCost concept push to sell Power to give a good white space ratio, zCost  allows  partially to “auto finance” this power’ purchase by the financial savings gained on the software billing.”