This paper presents the idea that the life cycle of an ontology is highly impacted as a result of the process of reusing it for building another ontology. One of the more important results of the experiment presented is how the different activities to be carried out during the development of a specific ontology may involve performing other types of activities on other ontologies already built or under construction. We identify in that paper new intradependencies between activities carried out inside the same otology and interdependencies between activities carried out in different ontologies. The interrelation between life cycles of several ontologies provokes that integration has to be approached globally rather than as a mere integration of out implementation.