A temporal-spatial-domain distribution model and alignment method for quality attributes

Many software systems have been servitized into the form of service-based architecture, and their constituent service components are deployed in distributed ubiquitous environment. In terms of such type of systems, the quality perceived by massive users are diversified at different times, at different locations, or in different domains. This phenomenon is called Temporal- Spatial-Domain (TSD) distribution of quality attributes, and there is a TSD space Q for each quality attribute. When two service components offered by different providers collaborate with each other, there might be severe quality conflicts due to inconsistencies among quality standards adopted in different business domains and among subjective user perceptions at different locations or times. It is necessary to make alignment on values of quality attributes in terms of their TSD distributions. This paper presents a model to formally delineate the TSD distribution characteristics of quality attributes, and then uses Quality Contour Lines (QCLs) to represent equivalent user- perceived quality levels at different TSD points. A quality alignment method is proposed to eliminate quality inconsistencies based on pre-defined QCLs and Service Quality Levels (SQLs). This work extends traditional software/service quality models and could help facilitate more precise quality design and quality improvement for software/service developers.