Overview - ISO/IEC 23544:2021 (APEE)
ISO/IEC 23544:2021 defines Application Platform Energy Effectiveness (APEE) - a KPI for quantifying the energy effectiveness of an application platform (the combination of target IT equipment, operating systems and middleware) for an IT service in data centres. APEE is intended to evaluate energy consumption prior to deployment, helping organizations select an energy‑efficient IT stack. The standard specifies the APEE formula, component definitions, benchmark and measurement prerequisites, and reporting requirements. It explicitly excludes KPIs that only evaluate hardware or whole data‑centre facility efficiency.
Key topics and technical requirements
- APEE formula: APEE = NoAO / EAP
- NoAO = number of application outcomes during the measurement
- EAP = energy consumption (kWh) of the application platform during measurement periods
- Unit: application outcomes per kWh (recommendation: report at least 2 significant digits)
- Benchmark prerequisites:
- Benchmark must be representative of the target IT service
- Start and end of execution must be clearly defined
- Iterations must produce comparable results
- An application outcome must be identical across executions and platforms
- Measurement scope:
- Measurement uses defined measurement period(s) (e.g., query execution time)
- Energy consumption must be measured for the application platform components (servers, storage, network, OS, middleware) only
- Reporting:
- The document prescribes requirements for reporting APEE results, benchmark identifiers, measurement methods and conditions, and other metadata to ensure comparability and transparency
- Out‑of‑scope:
- Hardware‑only KPIs and data‑centre facility energy effectiveness are not covered
Applications and practical value
- Procurement: Compare candidate application platforms (hardware + OS + middleware) to select the most energy‑effective stack before purchase or deployment.
- Architecture & design: Inform decisions on middleware, DBMS, hypervisors, and OS choices to reduce energy consumption for a given application outcome.
- Capacity planning & optimization: Evaluate tradeoffs between performance and energy use for proposed IT platforms.
- Sustainability reporting: Provide standardized, comparable platform‑level energy KPIs for internal sustainability metrics and vendor evaluations.
Who should use it
- Data centre operators and IT infrastructure architects
- Procurement teams evaluating application platform proposals
- Software and middleware vendors demonstrating energy effectiveness
- Sustainability officers and benchmarking organizations
Related standards
- ISO/IEC 21836 - server energy effectiveness metric (related KPI for hardware)
- ISO/IEC 21878 - security guidelines for virtualized servers
(These provide complementary metrics and guidance; ISO/IEC 23544 focuses specifically on the combined application platform KPI - APEE.)
Keywords: ISO/IEC 23544:2021, APEE, Application Platform Energy Effectiveness, data centres, KPI, benchmark, middleware, operating system, energy consumption, energy effectiveness.