Engine Indication and Alerting System for Flight Crew provides flying crew with information about aircraft systems. This information covers both nominal and abnormal systems’ states as well as recommended remedial actions to handle abnormal situations. According to the complexity of systems to be managed (e.g. an aircraft engine) information and states must be abstracted away so that flying crew is not overwhelmed. We propose a double mechanism to support such activity: a generic description of states of aircraft systems called OQCR and a hierarchical decomposition of aircraft systems architecture called DSCU. We show how these two contributions provide systematic means to represent aircraft systems and their relationships as well as their nominal and abnormal states. We demonstrate their application on two system pages from large commercial aircraft showing how they can be used to support HMI designs. We also highlight how these contributions can be generalized to other domains.