Elementary Net Systems with Localities (ENL-systems) is a class of Petri nets introduced to model GALS (globally asynchronous locally synchronous) systems, where some of the components might be considered as logically or physically close and acting synchronously, while others might be considered as loosely connected or residing at distant locations and communicating with the rest of the system in an asynchronous way. The specification of the behaviour of a GALS system comes very often in the form of a transition system. The automated synthesis, based on regions, is an approach that allows to construct Petri net models from their transition system specifications. While theory of regions is well developed, there is still lack of implemented tools capable of dealing with complex real-life system construction. In this paper we focus on developing algorithms and tool support for the synthesis of the ENL-systems from step transition systems, where arcs are labelled by steps (sets) of executed actions. The algorithms are implemented within the workcraft framework.