Applying ADD Model to Enhance Quality of SOA Applications

SOA enables integration of applications and resources flexibly, representing every application or resource as a service. Its purpose is to facilitate reuse and interoperability of applications, which are regarded as quality attributes of a system. It is very easy to talk about the benefits of SOA (reuse, etc.). But, there are no precise specifications to define this concept as the architectural style. SOA has another shortcoming; it is a problem of performance related to the creation of services that affect the total processing time of the system. This paper provides a basic specification of SOA and identifies architectural tactics to improve performance. The tactics adopted for the performance are then validated by a case study. A solution for the development of tactics is to use the ADD method. This is a method to meet the architectural requirements or qualities expected from a system. Three architectural models have been well integrated into SOA. Validation of the case study determined that the tactics are working and it is interesting to use in SOA architecture. However, an interesting point that arises from the test is that the decomposition model of service can be used with caution. Two contributions emerge from this paper: a basic specification and a design of SOA-based integration models (architectural) to improve performance. The main recommendation arising from this test is the addition of tactical or creating tools to automate the architecture chosen and thus improve performance. DOI: 10.4018/jbdcn.2012100105 68 International Journal of Business Data Communications and Networking, 8(4), 67-83, October-December 2012 Copyright © 2012, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. 2002; He, 2003; Rotem-Gal-Oz, 2011) which are well known, it seems, it does not exist precise specification (architectural elements) for the SOA style in general. SOA is rather perceived by companies as a way to support the business processes of the enterprise (Raymond, 2011). In short, it is very difficult to talk about SOA as an architectural style (architectural style is a set of principles; a coarse grained pattern that provides an abstract framework for a family of systems) because of the lacks of information or specification about elements in SOA architecture. However, there are some efforts trying to define SOA specification. OASIS (Organization for the Advancement of Structured Information Standards) for example has worked for six years on a SOA reference model. Their approach can be summarized in three objectives: establishing definitions, unifying concepts existing SOA, creating a clear semantics for modeling SOA solution. Despite this, the lack of precision of SOA is still a big challenge, because SOA has a varied nature. At this first problem, we can talk about another problem concerning SOA. This is the problem of performance. This can be explained in the following way: the notion of abstraction and ease of creation of services within SOA lead to many small interactions between the different systems (applications) created, which dramatically affects the performance of the whole (Heubès, 2008). Another way to express this problem is the access time and availability (Crochet-Damais, 2007). Improve the access time and availability in a system is also a task or a challenge for architect. It’s the reason of that, apart from the need to answer the question of a definition of SOA (specification), our second objective is to provide tactical and architectural approaches to improve this performance problem. We will focus on two important points, firstly, propose a specification (definition) to a better understanding of SOA and secondly to apply a technique to improve performance. For this second purpose, we will use the ADD method to support performance. Note that ADD is a method of creating architecture based on the quality attributes (Wojcik, 2006). In this paper, we will talk about our two contributions. The first focuses on a specification or definition of SOA. The second offers in addition to the specification, a way to meet the performance (an extension to improve SOA model) using the ADD method. A series of case study is made to validate the performance of applications with ADD.