arXiv:2610.31815v1 Announce Type: new Abstract: This paper considers the identifiability of dynamical networks whose topology is a Directed Acyclic Graph (DAG), in the context where not all nodes are excited and not all nodes are measured. The objective is to construct a valid and parsimonious Excitation and Measurement Pattern (EMP), i.e. a selection of excited and measured nodes, that allows to identify the whole network with a small number of excitations and measurements. We show first that a DAG can be decomposed into a set of trees and parallel paths networks. We propose an algorithm that achieves this decomposition and computes an EMP that combines EMPs for the individual trees and parallel paths networks. We formally show that this algorithm yields an EMP capable of identifying the whole network.