Method of using tickets and use cost values to permit usage of a device by a process

A method comprising:

• monitoring a plurality of environmental information associated with a computer system;
• setting a use cost value for a device within said computer system based on said monitored environmental information;
• assigingng a plurality of applications being executed in said computer system into a first group, a second group and a third group;
• allocating, by a central processor unit, tickets to processes of said applications at respective accumulation rates, wherein the respective accumulation rates are based on the particular group to which the respective applications associated with the respective processes belong, wherein processes of applications in a same group have equal accumulation rates;
• in response to a request by a process to use a device, determining whether or not a number of tickets held by said process is greater than a use cost value currently associated with said requested device;
• and
• in response to a determination that said number of tickets held by said process is greater than said use cost value currently associated with said requested device, permitting usage of said requested device by said process.