You can't fix, manage or justify what you don't understand. IT chargeback/trackback not only helps end users understand their service utilization, but it also helps IT justify and prioritize spend. Measured service is a requirement of NIST's cloud definition:
"Cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported, providing transparency for both the provider and consumer of the utilized service."
In a public cloud setting, the requirement for measured service is apparent: Customers will utilize resources and be billed for use, therefore metering must be in place for those resources. In private cloud settings the financial aspects are typically more blurred, therefore measured service's value is less obvious.
Many IT organizations rely on lackluster or completely nonexistent departmental budgeting for IT resources. IT itself is considered a cost center and provided a budget from which to deliver all of the required business services. This makes it difficult if not impossible to prioritize new projects and ensure that IT is providing services appropriately to business units based on tangible factors. These weaknesses will be further magnified in private cloud models.
IT chargeback/trackback systems are just as important to private cloud success as they are public. Regardless of whether or not business units are directly billed for IT services, having visible usage metrics provides a great deal of benefit and can help keep your private cloud journey on track. The key benefits of IT chargeback/trackback systems to private clouds are visibility, prioritization and accountability.
The primary benefit of visibility is a decrease in needless service usage/deployment. Regardless of whether business units are being charged back, showing them their costs can help reduce waste. Making the internal costs of deployed services visible to business leaders forces them to acknowledge that they are not free and will help to reduce careless use. Additionally, with tools in place to monitor per-department IT spend, reduction in IT services spend can be incentivized by management.
Prioritization of new projects is always difficult, but it becomes more so the less information you have available to make the call. With IT chargeback/trackback in place, you have data that's vital to making prioritization decisions. When projects compete for limited resources, it will be far easier to identify current resource spend for each department and weigh that against both the department itself and estimated value of the new service.
Accountability is key to ensuring proper usage of IT resources. For example, if two departments of equal size--A and B--are using significantly disparate resource amounts, it can send a flag for further investigation. This could go both ways--maybe there are resources being used by department A that could benefit department B, or maybe department A is overusing resources unnecessarily. Additionally, accountability can play a role with demanding departments that may show little to no value from new services.
Lastly, IT chargeback/trackback will help validate and promote your private cloud deployment. Showing adoption rates and usage will be key to maintaining momentum as you roll out a private cloud architecture. This will also assist in recognizing departments that are slower to adopt in order to identify gaps in offerings or promotion of those offerings.
Regardless of the cloud deployment model chosen, IT chargeback/trackback is an integral requirement. Properly understanding and utilizing an IT chargeback/trackback tool set will assist in both deployment and operation of your private cloud. Don't let implementation of these tools fall to the wayside.