This paper tries to explain some points related to the time properties in distributed real-time systems relevant of the NOAH-WP4. It is partly deduced from the input paper of ENEL and from the definition of WP4 in the technical appendix of NOAH project. All the problems related to system aspects and to the distribution are relevant of the WP4. It is then important to define a common view on these points for the requirements definition. The first section deals with another approach stating the problem already explained in [1]. We distinguish the functional and the operational architectures in order to point out the distribution problems and the necessity for special mechanisms, algorithms or protocols in order to meet the different constraints and properties. The second and third sections deal with the DBR and MIB and with the management relationships. They introduce the timeliness properties which are classified in the 4th section according to a temporal logic. Some examples are then given.