A Classification of Enterprise Service-Oriented Architecture

2010 Fifth IEEE International Symposium on Service Oriented System Engineering

A Classification of Enterprise Service-Oriented Architecture

Longji Tang, Jing Dong, Yajing Zhao Department of Computer Science University of Texas at Dallas Richardson, TX 75083, USA

{ltang,jdong,yxz045100}@utdallas.edu

Abstract

Enterprise Service-Oriented Architecture (ESOA) style defines the principles and guidelines for designing and implementing complex business processes and systems. This paper classifies ESOA style to six substyles based on a domain model of service-oriented enterprise and an abstract model we proposed. The definition of each style is provided. A comparison of parts and constraints of five basic ESOA styles is also presented. Finally, we conclude by comparing related work of ESOA style classification and discussing the benefits of our research work for both research and practice in ESOA.

1.Introduction

As a special type of Service Oriented Architecture (SOA), Enterprise SOA (ESOA) is a new enterprise software architectural style that is an abstraction of concrete SOA architectures in enterprises. ESOA combines SOA basic principles and constraints with specific enterprise architecture environment and business requirements (functional and non-functional). Many architectures, such as Amazon web service architecture, IBM SOA-based enterprise architectures, in service-oriented enterprises are the instances of ESOA. ESOA and its substyles focus on service orientation and loose-coupled integration, and promote interoperability [6], agility, performance, reliability, reusability and extensibility for enterprise business interests. Enterprise systems consist of complicate applications in heterogeneous environment. ESOA can better help application integration because of its interoperability and relatively loose coupling service nature.

While ESOA has been applied in different business systems, it lacks a classification of different ESOA which impedes the understanding and application of SOA. Through our research [7][25][26][29] for enterprise SOA architecture, we recognize the need for

Wei-Tek Tsai

Department of Computer Science and Engineering Arizona State University, Tempe, AZ 85287, USA

& Tsinghua University, Beijing, China

wtsai@asu.edu

the model of enterprise service-oriented architecture, which shows how a model can help understanding complex systems. We also realize the need for the enterprise SOA architectural styles, which can help designing better information systems and satisfying the business needs and reducing enterprise IT complexity and cost.

Our work in this paper includes classifying ESOA styles to six substyles based on a domain model and the abstract model we proposed in [25], defining each ESOA style and their hierarchy, and comparing five basic ESOA architectural styles in their parts and constraints by using our model and ESOA style analysis methodology. Our research work on ESOA styles classification can help at understanding the complicate ESOA architectures and guiding better design of ESOA systems.

This paper is organized as follows: Section 2 discusses the domain model of service-oriented enterprise; Section 3 defines a classification of ESOA architectural styles; Section 4 provides a comparison among different ESOA sub-styles; Section 5 discusses the related work; Section 6 summarizes conclusions of this paper.

2.Domain Model of Service-Oriented Enterprise

Before defining and discussing our ESOA architectural styles, we describe the characteristics of modern enterprise architecture. Specifically we characterize the architectural context in service-oriented enterprise. Our purpose is primarily to provide a domain model for our abstract model proposed in [25], since the model will be the base on describing and classifying all ESOA styles. Table 1 summarizes various characteristics of modern enterprise information systems.

The characteristics of enterprise information systems are also the basic characteristics of enterprise architecture, which indicate the complexity, requirements and concerns in designing enterprise

architecture. Enterprise Application Integration (EAI) as an integration style provides the principles for building middleware-centric enterprise architecture, such as SUN’s J2EE, Microsoft .NET, and has aided in solving more and more complicated enterprise systems integration issues from early 2000. However traditional EAI did not fully resolve enterprise integration issues because of tight-coupled traditional EAI architecture, Figure 1 depicts architectural entities and their relationships within service-oriented enterprise through a domain model and reflects the characteristics found in Table 1. It is the foundation of our study on generic ESOA architectural model and styles. Compared with other styles, such as client-server, component-based EAI, ESOA styles are service-oriented. The major architectural entities in service-oriented enterprises lack of good interoperability, and poor scalability as well as security. ESOA, as a better approach than EAI, has been broadly adopted by enterprise since 2003 [14]. ESOA is a new architectural style which is a general SOA style for enterprise architectures. Customer facing

xcustomers’ requirements

xcustomers

x

Systems serves customers and meet business demands

Heterogeneousenvironment

xstructure

x

products

Distributedcomputing

enterprise networks

x

distributed through the Internet Integration

xintegrated with existing legacy systems

x

enterprises are integrated.

Manage and access customer/business xBusiness and customer data is managed and can be accessed data

xSystem data is managed and can be accessed

processes Meet certain non-functional xPerformance requirements xx