Research On Task And Resource Allocation Algorithms In WfMs

The emergence of a truly global economics has immersed all businesses into an intensively competitive environment moving with accelerating rates of changes. Gradual improvements in productivity and enhancements in quality are no longer enough to maintain market leadership. The fast delivery of new products/services and the rapid modification of existing applications are key survival factors. These requirements have forced enterprises to look for new solutions, and workflow has emerged as one of the crucial technologies to meet these needs.Workflow management systems (WfMS) are software systems supporting the automatic execution of workflows. WfMSs are designed to support business processes. A business process consists of a number of steps (activities) that can be executed automatically, manually, or using a combination of these two. Resource allocation and task assignment of WfMS are a crucial role in workflow dispatching, which apparently is also the premise for the efficiency and productivity of WFMS execution as a whole.This thesis focuses on the synthesis of the performance features that effect the task execution, offering a dependable algorithm mechanism for performance analyzing, based on which, a highly effective method for task assignment, authority delegation is also provided.Resource allocation and scheduling are fundamental issues in a Workflow Management System. Effective resource management in WfMS should examine resource allocation together with task scheduling since these problems impose mutual constraints. Optimization of the one factor is subject to the other constraints and vice versa. Thus, an ideal algorithm should take into account not only performance metrics of the infrastructure, such as the number of resources and their utilization, but also quality criteria such as the percentage of tasks undergone violation in their temporal restrictions. In this paper, we propose an innovative algorithm which jointly optimizes the two aforementioned contradictory criteria. The algorithm, called resource conflicts joint optimization, minimizes resource conflicts subject to temporal constraints and simultaneously optimizes throughput or utilization subject to resources constraints. To achieve the optimization, the two factors are formulated in matrix form and the optimal solution is found by applying concepts of the generalized eigenvalue analysis. A rough outline of an agent based architecture is proposed to achieve runtime integration of our algorithm into a functional WfMS, while experimental results under different load environments and tasks assumption reveal the superiority of the proposed strategy than the other conventional approaches.