**3.3.2 Planning Application Ontology**

The Plan Application Ontology is used to express the *SAV* of the mission planner agent. It uses concepts originally defined by the *Planning Domain Definition Language* (PDDL). The PDDL language was originally created by Ghallab et al. (1998) to standardise plan representation. Concepts are extracted from the language vocabulary and the language grammar is used for describing the relationships and constraints between these concepts.

For the adaptation mission planning process, the Planning Application Ontology also requires concepts capable of representing the diagnosis of incidents or problems occurring in some parts of the mission plan (van der Krogt, 2005). Some of the most important concepts identified for mission plan adaptability are:


Please note how some of these concepts are also related to concepts of the Core Ontology (e.g. a list of *capability* concepts is required to perform a mission *action*).
