Abstract: By introducing concepts of the scheduling-decision-variable and decision space and on the basis of the dynamic-marking for TCPN, this paper presents a calculation method for firable and schedulable decision domain of the transitions, which lead to a target mark. Besides, a transition will last for a period of time, so it is not certain that its firing can be completed successfully even if the transition has been fired. Thus the reaching possibility of an expected target may also depend on the failure or extermination of other transitions. Therefore, those failing transitions should be considered when we deal with schedulability analysis and system synthesis of TCPN. TCPN with weak firing mode can be used to manage dynamic scheduling of concurrent and distributed real-time control systems with deadline and releasable resources.