Noname manuscript No. (will be inserted by the editor) Shrinking of Time Petri nets Didier Lime* · Claude Martinez** · Olivier H. Roux* the date of receipt and acceptance should be inserted later Received: date / Accepted: date Abstract The problem of the synthesis of time bounds enforcing good prop- erties for reactive systems has been much studied in the literature. These works mainly rely on dioid algebra theory and require important restrictions on the structure of the model (notably by restricting to timed event graphs). In this paper, we address the problems of existence and synthesis of shrink- ings of the bounds of the time intervals of a time Petri net, such that a given property is verified. We show that this problem is decidable for CTL proper- ties on bounded time Petri nets. We then propose a symbolic algorithm based on the state class graph for a fragment of CTL. If the desired property “in- cludes” k-boundedness, the proposed algorithm terminates even if the net is unbounded. A prototype has been implemented in our tool Romeo and the method is illustrated on a small case study from the literature. Keywords Time Petri nets, time interval shrinking, model-checking, state-class graph. 1 Introduction Production control problems in manufacturing are often modeled as Discrete Event System (DES) control problems and Petri nets are widely used to tackle such kind of control problems (Cassandras and Lafortune 1992; Li and Zhou 2009). Some production systems are subject to strict time constraints in the dura- tion of some particular tasks in their manufacturing process such as chemical This work has been partially supported by project ImpRo ANR-2010-BLAN-0317. *LUNAM Universit´ e, ´ Ecole Centrale de Nantes, IRCCyN UMR CNRS 6597 firstname.name@irccyn.ec-nantes.fr · ** LUNAM Universit´ e, Universit´ e de Nantes, IRCCyN UMR CNRS 6597 firstname.name@univ-nantes.fr