Introduction

In the SQuaRE series, there are well-defined quality models for measuring and evaluating system and software products, IT services, data, etc. Although the SQuaRE series provides practical quality models, it does not fit new technologies well. To support the evaluation of new technologies, this document provides the quality model of cloud services, which is the extension to the quality models defined in ISO/IEC 2501n. In order to provide a practical guideline for quality evaluation of cloud services, this document has reflected special considerations on cloud computing, which are key characteristics, and cross-cutting aspects described in ISO/IEC 17788, and service level agreement (SLA) framework described in ISO/IEC 19086 (all parts).

Compared to the information and communication technology (ICT) systems, cloud computing has different characteristics. The followings are the key characteristics of cloud computing described in ISO/IEC 17788.

— Broad network access: physical or virtual resources are available when needed through the network using a variety of client devices.
— Measured service: resources are measured and paid for on a usage basis.
— Multi-tenancy: physical and virtual resources are allocated to multiple tenants, and their computations and data are isolated, therefore inaccessible from one another.
— On-demand self-service: cloud services are provisioned by cloud service customers automatically or with minimal interaction with cloud service providers.
— Rapid elasticity and scalability: resources are increased or decreased rapidly and elastically, and scalable horizontally and vertically.
— Resource pooling: physical or virtual resources are aggregated to provide services to one or more cloud service customers.

The quality model in this document is to support the non-functional specification and evaluation of cloud services from different perspectives by those associated with cloud service selection, requirements analysis, development, use, evaluation, support, maintenance, quality assurance and control, and audit.

For example, activities during cloud service selection that can benefit from the use of the quality model include:

— identifying cloud services requirements;
— establishing cloud service selection criteria;
— defining service coverage and service objectives;
— establishing service level agreements;
— establishing measures of quality characteristics in support of these activities.

Activities during cloud service development that can benefit from the use of the quality model include:

— identifying cloud service requirements;
— validating comprehensiveness of requirement definitions;
— identifying cloud service design objectives;
— identifying cloud service testing objectives;
— identifying quality control criteria as part of quality assurance;
— identifying acceptance criteria for a cloud service;
— establishing measures of quality characteristics in support of these activities.

Figure 1 (adapted from ISO/IEC 25000) illustrates the organization of the SQuaRE series representing families of standards, further called divisions. This document belongs to extension division 25050 to 25099.

Figure 1 — Organization of the SQuaRE series of International Standards

The divisions within the SQuaRE series are:

— ISO/IEC 2500n - Quality management division. The International Standards that form this division define all common models, terms and definitions further referred to by all other International Standards from the SQuaRE series. The division also provides requirements and guidance for a supporting function that is responsible for the management of the requirements, specification and evaluation of software product quality.
— ISO/IEC 2501n - Quality model division. The International Standards that form this division present detailed quality models for computer systems and software products, quality in use, and data. Practical guidance on the use of the quality models is also provided.
— ISO/IEC 2502n - Quality measurement division. The International Standards that form this division include a quality model framework, mathematical definitions of quality measures, and practical guidance for their application. Examples are given of quality measures for software quality, and measures for quality in use. Quality measure elements (QME) forming foundations for these measures are defined and presented.
— ISO/IEC 2503n - Quality requirements division. The International Standards that form this division help specify quality requirements, based on quality models and quality measures. These quality requirements can be used in the process of quality requirements elicitation for a software product to be developed or as input for an evaluation process.
— ISO/IEC 2504n - Quality evaluation division. The International Standards that form this division provide requirements, recommendations and guidelines for software product evaluation, which are performed by evaluators, acquirers or developers. The support for documenting a measure as an evaluation module is also presented.
— ISO/IEC 25050 to ISO/IEC 25099 - SQuaRE extension division. This division includes International Standards specifying requirements for quality of ready to use software product and common industry formats for usability reports, as well as this document.

PD ISO/IEC TS 25052-1:2022

Systems and software engineering. Systems and software Quality Requirements and Evaluation (SQuaRE): cloud services - Quality model

Current, Under Review

Published:

31 Oct 2022