本文档定义了云服务的质量模型。 云服务的质量模型由九个特征组成（其中一些特征进一步细分为子特征），这些特征为指定、测量和评估云服务提供了一致的术语，以便利益相关者、云服务客户（CSC）、云服务提供商（CSP）和云服务合作伙伴（CSN）有一个共同的理解。 由于本文件中的质量模型是ISO/IEC？中定义的现有质量模型的扩展2501n，根据评估目的，它可以与产品质量模型、it服务质量模型、数据质量模型和使用质量模型一起使用。 由于有几个云服务类别，本文档重点介绍SaaS（软件即服务）的质量模型。 注意未来的文档旨在讨论PaaS（平台即服务）和IaaS（基础设施即服务）。

This document defines the quality model of cloud services. The quality model of cloud services is composed of nine characteristics (some of which are further subdivided into subcharacteristics), which provide consistent terminology for specifying, measuring and evaluating cloud services so that the stakeholders, cloud service customer (CSC), cloud service provider (CSP) and cloud service partner (CSN) have a common understanding. Since the quality model in this document is the extension to the existing quality models defined in ISO/IEC？2501n, it can be used with the product quality model, IT service quality model, data quality model, and quality-in-use model according to evaluation purposes. As there are several cloud service categories, this document focuses on the quality model of SaaS (Software as a Service). NOTE？Future documents are intended to address PaaS (Platform as a Service) and IaaS (Infrastructure as a Service).