Automated Service Composition for Software Customization

While Service-Oriented Architecture helps the realization of Software Product Line, the current practice of manual composition of service components has become a bottleneck for the automation of customized software production. The web service-based applications are increasing in the present days. The use of web services for the development of the software with the idea of product line is a new feature. This approach not only uses clients\u27 requirements for the identification of candidate services, but also takes sensitivity into consideration when deciding the most suitable ones for a particular custom-made software system. This enhancement of service selection and composition leads to the development of an enhanced framework of service integration life-cycle, whose operation is presented in a new algorithm in this thesis. In addition to details of the framework, a case study is also included to examine the process of candidate identification, sensitivity analysis, service selection, and system composition for a customized online shopping system

WEB SERVICES COMPOSITION METHODS AND TECHNIQUES: A REVIEW

ABSTRAC

Concept Trees: Building Dynamic Concepts from Semi-Structured Data using Nature-Inspired Methods

This paper describes a method for creating structure from heterogeneous sources, as part of an information database, or more specifically, a 'concept base'. Structures called 'concept trees' can grow from the semi-structured sources when consistent sequences of concepts are presented. They might be considered to be dynamic databases, possibly a variation on the distributed Agent-Based or Cellular Automata models, or even related to Markov models. Semantic comparison of text is required, but the trees can be built more, from automatic knowledge and statistical feedback. This reduced model might also be attractive for security or privacy reasons, as not all of the potential data gets saved. The construction process maintains the key requirement of generality, allowing it to be used as part of a generic framework. The nature of the method also means that some level of optimisation or normalisation of the information will occur. This gives comparisons with databases or knowledge-bases, but a database system would firstly model its environment or datasets and then populate the database with instance values. The concept base deals with a more uncertain environment and therefore cannot fully model it beforehand. The model itself therefore evolves over time. Similar to databases, it also needs a good indexing system, where the construction process provides memory and indexing structures. These allow for more complex concepts to be automatically created, stored and retrieved, possibly as part of a more cognitive model. There are also some arguments, or more abstract ideas, for merging physical-world laws into these automatic processes.Comment: Pre-prin

An Investigation into Dynamic Web Service Composition Using a Simulation Framework

[Motivation] Web Services technology has emerged as a promising solution for creat- ing distributed systems with the potential to overcome the limitation of former distrib- uted system technologies. Web services provide a platform-independent framework that enables companies to run their business services over the internet. Therefore, many techniques and tools are being developed to create business to business/business to customer applications. In particular, researchers are exploring ways to build new services from existing services by dynamically composing services from a range of resources. [Aim] This thesis aims to identify the technologies and strategies cur- rently being explored for organising the dynamic composition of Web services, and to determine how extensively each of these has been demonstrated and assessed. In addition, the thesis will study the matchmaking and selection processes which are essential processes for Web service composition. [Research Method] We under- took a mapping study of empirical papers that had been published over the period 2000 to 2009. The aim of the mapping study was to identify the technologies and strategies currently being explored for organising the composition of Web services, and to determine how extensively each of these has been demonstrated and assessed. We then built a simulation framework to carry out some experiments on composition strategies. The rst experiment compared the results of a close replication of an ex- isting study with the original results in order to evaluate our close replication study. The simulation framework was then used to investigate the use of a QoS model for supporting the selection process, comparing this with the ranking technique in terms of their performance. [Results] The mapping study found 1172 papers that matched our search terms, from which 94 were classied as providing practical demonstration of ideas related to dynamic composition. We have analysed 68 of these in more detail. Only 29 provided a `formal' empirical evaluation. From these, we selected a `baseline' study to test our simulation model. Running the experiments using simulated data- sets have shown that in the rst experiment the results of the close replication study and the original study were similar in terms of their prole. In the second experiment, the results demonstrated that the QoS model was better than the ranking mechanism in terms of selecting a composite plan that has highest quality score. [Conclusions] No one approach to service composition seemed to meet all needs, but a number has been investigated more. The similarity between the results of the close replication and the original study showed the validity of our simulation framework and a proof that the results of the original study can be replicated. Using the simulation it was demonstrated that the performance of the QoS model was better than the ranking mechanism in terms of the overall quality for a selected plan. The overall objectives of this research are to develop a generic life-cycle model for Web service composition from a mapping study of the literature. This was then used to run simulations to replicate studies on matchmaking and compare selection methods

An integration life cycle for semantic Web services composition

Business applications are more and more often developed on the basis of Web services. The aim is to provide platform independence and loose coupling between business applications to facilitate distributed and grid computing scenarios. However, most efforts to deploy and publish Web services are manual. Manual discovery, invocation and composition of Web services in a distributed computing environment significantly hamper the automatic process of enterprise application integration. Semantic enhancements in Web services aim at making the process of Web services discovery, invocation and composition dynamic by exposing the machine understandable description of Web service capabilities and Web service requests. In this paper we compare recent dynamic Web service composition approaches. We highlight some dynamic composition issues and compare existing approaches with respect to these issues. Based on these findings we present a new and generic semantic Web services integration and composition lifecycle tofacilitate the semantic based integration and composition of Grid services. The proposed semantic Web services integration and composition life cycle explains the necessary integration phases beginning with the modeling and developing of processes as Web service composition and ending with their execution. With this lifecycle, integration hurdles among diferent service composition approaches will be diminished