Allocation and chargeback policy for PaaS storage services
A mathematical rebilling model built for shared storage blocks. Idle capacity identified and charged back to IT to reduce waste.
01 Challenges and context
Context and strategic stakes
A major industrial client sought to implement showback and chargeback for their high-performance Cloud storage service (NetApp Volumes on GCP) to their business units. This complex service relied on shared and mutualized storage blocks across countless applications and environments (Dev, Prod), making direct financial attribution impossible. The dual FinOps challenge was to devise an equitable mathematical model to allocate these shared costs (backups, network) and to empower teams to address capacity waste (overcommit) inherent in this technology.
02 Work carried out
Approach and methodology
We developed a two-tiered semantic policy specifically tailored for NetApp Volumes. The first level of tagging targeted the container (the "Storage Pool") to allocate the overall cost of provisioned capacity. The second level targeted the content (the logical "Volume") to allocate induced usage costs (network bandwidth, replication, backups). We standardized the application of 5 mandatory metadata keys: Application, Environment, Cost Center, Owner, and Business Unit.
03 Outcomes achieved
Results and indicators
98%
of costs traced
Excellent traceability: Successful application of the labeling model to 98% of costs related to the NetApp Volumes service.
Business transparency: Implementation of an impeccable and accepted budget allocation for mutualized storage volumes.
IT optimization: Significant reduction in hardware waste through increased visibility of unused capacities, directly charged to the IT department.