Petri nets are a powerful formalism in modeling workflows. A workflow determines the flow of work according to pre-defined business process definitions. In many situations, business processes are constrained by scarce resources. The lack of resources can cause contention, the need for some tasks to wait for others to complete, and the slowing down of the accomplishment of larger goals. In our previous work, a resource-oriented workflow nets (ROWN) based on two-transition task model was introduced for resource-constrained workflow modeling and analysis. Considering the possibility of task failure in the middle of execution, we propose a three-transition task model to specify a task's start, end and failure in this paper. Resource requirements for general workflow can be done through reachability analysis. For a class of well-structured workflows, an efficient resource analysis algorithm is developed.