Abstract: The invention relates to a successive-actuation device of the type including at least one pyrotechnic cord and a trigger for actuating the operation thereof. Advantageously, the invention contains at least one element made from a shape-memory alloy having two stable states and disposed along the pyrotechnic cord, the element being capable of actuating a subsequent operation when it passes from one of its two stable states, for which the element occupies a neutral position, to its other stable state for which is occupies an active position, under the action of the heat generated by the pyrotechnic cord after triggering.