Formalising Service-Oriented Design

Abstract

<p class="MsoNormal" style="text-align: left; margin: 0cm 0cm 0pt; layout-grid-mode: char;" align="left"><span class="text"><span style="font-family: ";Arial";,";sans-serif";; font-size: 8.5pt;">Service-Oriented Computing (SOC) is an emerging paradigm for developing software systems that employ services. Presently there is already much research effort in the areas of service discovery and orchestration, business process modelling, and the semantic web. While these are all important aspects for moving towards the pervasive adoption of SOC, most existing work assumes the existence of black box services, with little attention given to how such services might be developed in a systematic manner. Furthermore, a precise description of what constitutes a service-oriented system is yet to be formally defined, and the overall impact of service-orientation on the software design process is not well understood. Therefore, this work presents a formal model covering design artefacts in service-oriented systems and their structural and behavioural properties. The model promotes a better understanding of service-oriented design concepts, and in particular, enables the definition of software metrics in an unambiguous, formal manner. Defining such a model and metrics is an initial step towards deriving a comprehensive service-oriented software design methodology.</span></span><span style="font-family: ";Arial";,";sans-serif";; font-size: 8.5pt;"></span></p

Evaluation of Service Designs Based on SoaML

“…There are a number of works proposing metrics for measuring the attributes of serviceoriented software. Perepletchikov et al [11] extend the generic software model of Briand [30] to propose a formal model for "structural and behavioral properties" of serviceoriented software and introduce metrics for measuring cohesion [10] and coupling [12]. Rud et al [13] describe metrics for measuring the granularity of services; Hirzalla et al [14] focus on flexibility.…”

Rule-Based Service Modeling

“…The establishment of a service-orientation requires the identification of the necessary services and their capabilities [3,15]. Before these services can be implemented, a service inventory blueprint describing the potential services and their capabilities in a conceptual manner is required.…”

Fine-Grained Metrics of Cohesion Lack for Service Interfaces

“…As already discussed (Section 1), the latter requirement (i.e., exactly matching input/output data types) may lead to the overestimation of cohesion lack. Another problem that may also negatively affect the precision of SISC and SIDC is that the approach proposed in [10], [11], [12] for the calculation of the metrics values does not make any distinction between normal input/output data and meta-data that are common in all operations.…”

“…However, they can not be used to reflect the relevance of the operations of service interfaces. Generally, in SOA the state of the art on cohesion metrics for service interfaces is limited to the work of Perepletchikov et al [10], [11], [12]. In this line of research the authors consider various notions of cohesion and propose corresponding metrics.…”

“…Specifically, for sequential and communicational cohesion, there exist coarse-grained metrics of cohesion lack, which consider that the operations of a service interface are related if the types of certain of their input/output data exactly match [10], [11], [12]. A limitation of these metrics is that operations which operate on data characterized by similar, but not exactly matching, types are treated as being totaly unrelated.…”