Overview
ISO/IEC TR 23951:2020 - Information technology - Cloud computing - Guidance for using the cloud SLA metric model provides practical guidance for applying the metric model defined in ISO/IEC 19086-2. Its scope is to describe how to use the ISO/IEC 19086-2 metric model and to illustrate that guidance with worked examples (for example, Cloud Service Mean Response Time and Simple Cloud Service Availability). The report complements the metric model with a practical, tabular representation and templates to help design, document and share cloud SLA metrics.
Key technical topics and requirements
- Metric model guidance: Explains how to apply the ISO/IEC 19086-2 model to compose measurable metrics for cloud SLAs.
- Tabular representation & templates: Introduces a refined tabular format (templates) that maps metric elements, expressions, rules and parameters for consistent documentation and reuse.
- Metric elements covered: Metric, Expression, Rule, Parameter (with examples and structured layouts).
- Example metrics: Detailed walkthroughs for Cloud Service Mean Response Time and Simple Cloud Service Availability, demonstrating informal and more formal metric variants.
- Guidelines for metric design: Practical guidance (Guidelines 1–7) on expression and rule languages, rule-expression associations, identifier practices, use of parameters and constants.
- Usage patterns: Use cases for extracting, clarifying, creating, comparing and cataloging metric descriptions from SLAs.
- Normative references: Works with related standards such as ISO/IEC 17788, ISO/IEC 17789, ISO/IEC 19086-1 and ISO/IEC 19086-2.
Practical applications and who uses this standard
ISO/IEC TR 23951:2020 is aimed at professionals and organizations involved in cloud contracting, measurement and compliance:
- Cloud service providers (CSPs) - to define clear, implementable metrics for SLOs and to document measurement logic in SLAs.
- Cloud service customers (CSCs) - to interpret SLA metric definitions, verify provider measurements and compare offerings.
- Cloud service partners (CSNs) and integrators - to standardize metric definitions across multi-party services.
- Regulators and policy makers - to understand how measurable commitments can be specified and audited.
- Tool and platform vendors - to implement metric catalogs, monitoring tools and SLA-compliance automation using the tabular templates.
Practical benefits include improved clarity of SLA commitments, repeatable metric definitions for automation, easier comparison of service offers, and a shared foundation for metric catalogs and audit processes.
Related standards
Keywords: ISO/IEC TR 23951:2020, cloud SLA metric model, ISO/IEC 19086-2, SLA metrics, cloud service availability, mean response time, SLA templates, metric catalog.