Workflow management systems allow workflows to be defined, executed, and managed with support of integrated organizational control. A workflow comprises a set of workflow activities which cooperate with each other to achieve the common goal of a business process. The significant improvement of workflow relevant technologies makes most business processes supported by workflow management systems. On the other hand, most existing workflow management systems have not considered performance to be an issue. But, many workflow applications such as telecommunications workflow processes require high performance workflow processing. In this regard, we in this paper propose three independent methods to improve the performance of a workflow.
Workflow applications often have timing constraints such that each processing of a workflow needs to be finished within its deadline. Previous works, however, have not much considered appropriate analyses to determine the processing capacities for certain activities so that most workflow instances can satisfy the deadline. As the first method for high performance workflow systems, we address a suitable scheme that can maximize the number of workflow instances satisfying the given deadline. Hence, we present a method to find out a set of critical activities where a
critical activity is the one whose delay of completion directly affects the overall processing time of a workflow. Since each critical activity must have a certain number of servers for the sufficient processing capacity, we then develop a method to determine the minimum number of servers for the critical activity such that this activity should be finished without delay for a given input arrival rate. We show through performance experiments that the method can be effectively utilized in practice.
Workflow time management is important in timely scheduling of workflow process execution, avoiding deadline violations, and improving the workflow throughput. Though there have be...