Chargeback
Charging each department or application for the mainframe resources it used, based on measurements the system records.
Also written showback, IT chargeback, cost allocation, job accounting
Chargeback means sharing the cost of the mainframe among the parts of the organisation that use it, according to how much each one uses. Showback is a lighter version that reports the costs without actually charging them.
The measurements come from SMF records. Each job and transaction is recorded with the processor time, storage and I/O it used, and the account or application it belongs to. Reports add these up by department, and a price for each unit turns usage into cost.
Processor time is usually the biggest part, because so much mainframe software is priced on processor usage. Storage, tape and printing may be charged too.
Chargeback changes behaviour. A team that sees the cost of a heavy job has a reason to make it more efficient. It also explains why accounting information on the JOB statement matters at some sites: it is how the job's cost reaches the right department.
Where can I learn this hands-on?
Right here, at ZedBank. You take a junior job at a simulated bank and learn each part of the work by doing it, with Zed beside you. There's nothing to install.
Start at ZedBankRelated
- SMFSystem Management Facilities: the z/OS feature that writes a detailed record of what happened on the system, used for billing, performance and security.
- MIPSMillions of instructions per second: the common, rough way of describing how much processing capacity a mainframe has.
- Capacity planningForecasting how much processor, memory and storage the mainframe will need, so there is enough before it is needed.
- Central processorA general purpose processor on the mainframe, the kind that runs z/OS work of any type.
- SLAService level agreement: an agreed target for a service, such as how available it must be or by what time a batch run must finish.