关键词: 工作流, 授权, 约束, 资源分配, 弹性, 可满足性

Abstract: Static [k] resiliency is concerned with the ability for workflows to recover executing from exceptions of resource unavailability. To verify it, up to [C(|U|,k)] Workflow Satisfiability（WS） decision problems should be solved（where [U] is the set of all resources） and the corresponding costs are huge. In existing work, one WS counting problem is solved to quantify the ability of a workflow to recover from exceptions. However, this indicator is somewhat rough, and only in the case of no satisfiability solution an accurate negative conclusion can be given. In this paper, for an exclusion and binding constrained workflow, a novel model which surrounds the concept of satisfiability counting lower bound of static [k] resiliency is established, and such a no-trivial lower bound is proved for the first time. Therefore, the negative condition of [k] resiliency is generalized, from unsatisfiable cases to satisfiable ones. This result has representative meanings in theory, by which the precisely applied range of the aforesaid indicator is also extended.

Key words: workflow, authorization, constraint, resource allocation, resiliency, satisfiability