Design of Workflows for Context-aware Applications

Abstract

Workflow technology is widely used for automation of business processes that supports their modeling, enactment, tracking, and analysis. Processes represented as workflows are composed of ordered and coordinated activities that integrate humans, resources, and applications. Workflow brings flexibility through explicit definition of processes enabling applications to be easily managed without disturbing the program code. Such unique characteristics of workflow technology enable it to be used in domains other than business also. In fact, workflow based programming brings a paradigm shift in the development of applications in more flexible, natural, and usable way. Recent advancement in communication, electronics, sensors, and software architectures pose requirements of context-aware applications that are dynamic, flexible, and adaptable. These applications are not limited to emerging domains like pervasive and ubiquitous computing but also required by traditional business processes to survive in today’s competitive market. The design and maintenance of context-aware applications may greatly be simplified by using workflows to represent variability associated with these applications. However, rigidity in workflow representation and enactment necessitates modifications and extensions in workflow technology before it could be adopted in context-aware application development. This thesis investigates key issues and challenges in adopting workflow technology for context-aware applications. Governed by the guiding principles of flexibility, adaptability, extensibility, reusability, autonomy, and usability; a generic framework for context-aware workflow design and management is presented. Making use of explicit modeling of context information, adaptation rule-set, and sub-workflows, a conventional workflow application may be transformed to become context-aware. A Context-Activity Architecture is presented that describes the integration and working of constituent components of context-aware workflow system. Most notably, an activity is represented as specially designed context-aware activity that adapts itself to a contextually suitable activity at runtime with the help of necessary functionality embedded within the activity itself. The proposed architecture is realized through the development of a context aware workflow designer tool (CAWD) using Windows Workflow Foundation classes. A couple of example scenarios and simulated testing elaborate and verify the intended adaptation operations and handling of evolutionary changes within a process that may be experienced by a context-aware workflow application.