1.1 added English labels. 1.2 changed name of CircumstantialPlan to GroundedPlan, as common in planning domain. Imports: DOLCE Ultralite 1.2 The Plan Ontology with a lite axiomatization. OWL engineering by Aldo Gangemi. Most workflow patterns are captured by the task notions introduced in this ontology. Several other notions relevant for plan modelling, assessment and creation are also introduced. A specialization of ending-task, aimed at sequencing events that end a plan execution without having reached its main-goal, but with the possibility or resurrecting the plan. Suspension task A loop task is a control task that has as successor an action -or complex- task that sequences at least two distinct activities sharing a minimal common set of properties -they have a MinimalCommonType. Notice that MinimalCommonType cannot be formalised as a first-order predicate, and then neither in OWL-DL. It can be considered a trivial guideline: when sequencing looped actions, choose a definite action class from the ground ontology. Some relations typically hold for loop tasks. Exit condition can be used to state what deliberation task causes to exit the cycle; iteration interval can be used to state how much time should be taken by each iteration of the looped activity; iteration cardinality can be used to state how many times the action should be repeated. Loop task The activity to generate a plan. Planning activity A control task is an elementary task that sequences a planning activity, e.g. an activity aimed at (cognitively or via simulation) anticipating other activities. Therefore, control tasks have usually at least one direct successor task (the controlled one), with the exception of ending tasks.The reification of control constructs allows to represent procedural knowledge into the same ontology including controlled action. Besides conceptual transparency and independency from a particular grounding system, a further advantage is enabling the representation of coordination tasks. For example, a manager that coordinates the execution of several related activities can be represented as a role with a responsibility (duty+right) towards some complex task. Control task A task defined in a plan assessment. Plan assessment task A task that has at least two other tasks as components. 2 Complex task The task joining the decision and preparation phases of the plan assessment, with the activation phases of the plan. Readiness task A goal situation is a situation that satisfies a goal.Opposite to the case of subplan executions, a goal situation is not part of a plan execution.In other words, it is not true in general that any situation satisfying a part of a description, is also part of the situation that satisfies the whole description. This helps to account for the following cases: a) Execution of plans containing abort or suspension conditions (the plan would be satisfied even if the goal has not been reached, see below), b) Incidental satisfaction, like when a situation satisfies a goal without being intentionally planned (but anyway desired). Goal situation A bag task is a complex task that does not include either a control task, or a successor relation among any two component tasks.The last condition cannot be stated in OWL-DL, because it needs a coreference. Bag task Spatial parameter Consideredness task The task sequencing a decision activity, aiming at if action has to be taken in order to start a plan execution. A case task is a task branched to a set of tasks that are not executable concurrently. In order to choose which task has to be undertaken, preliminary deliberation tasks should be executed, possibly based on information-gathering and decision rationales. BTW, the representation of decision making processes is not addressed in this ontology, and only a minimal formalization is provided as follows. A case task 'sequences' a decision-activity (a kind of mental event involving rationality) that has a deliberation-state as an outcome (i.e. it is 'sequenced-by' a deliberation-task). Case task Temporal parameter An activity aimed at gathering information for some purpose. It is typically sequenced by case tasks for taking decisions (can be part of decision activities). Information gathering A synchronization task is a merging aimed at waiting for the execution of all (except the optional ones) tasks that are direct successor to a concurrent or any order task. Synchro task Possibility task The task sequencing an activity from which the possibility is raised to execute a plan. Rejection task The task sequencing a negative decision to adopt a plan execution. A task that joins a set of tasks after a branching. Merging task A sequential task is a complex task that includes a successor relation among any two component tasks, and does not contain any control task.The first condition cannot be stated in OWL-DL, because it needs coreference. 2 Sequential task An action task is an elementary task that sequences non-planning activities, like: moving, exercising forces, gathering information, etc. Planning activites are mental events involving some rational event. Action task Circumstantial plan A grounded (aka 'circumstantial') plan has all components classifying named individuals from the ground ontology (e.g. only specific persons, specified resources, a finite number of time intervals and space regions, etc.). This is the typical outcome of a planner, which, given certain constraints (here modeled as a Plan), and available entities in the environment (resources, agents, actions), delivers an optimized 'ground plan' to be executed. Grounded plan Piano istanziato Spatially bound role 2 A case task branched to exactly 2 tasks, not executable in parallel. Alternate task An activity related to planning. It is supposed to execute a 'case task', and can contain an information gathering activity. Decision activity An activation task to start a plan execution after it has been suspended. Reactivation task A state related to planning. It is sequenced by 'deliberation task', and is preceded by a decision activity. When a plan is 'private', a decision state is cognitive, otherwise it depends on some cognitive state. Decision state The technique by which a planning process can be carried out. Planning as technique A maximal task is a complex task that has all the tasks defined in a plan as components.In OWL-DL the axiom is defined as a concept axiom over plan component task. Maximal task Acceptation task The task sequencing a positive decision to adopt a plan for execution. A specialization of ending-task, aimed at sequencing events that end a plan execution without having reached its main-goal, and with no intention to resurrect the plan. While 'abortion' depends on external causes, 'abandonment' depends on decisions. Abandonment task Preparedness task The task sequencing an assessment that the activities aiming at creating the prerequisites to start a plan execution are completed. The task sequencing a decision to take action in order to start a plan execution. Decidedness task A schedule is a task that cannot be executed twice, since it has a temporal parameter restricted to one value. In other words, a schedule classifies a specific event, which results to be 'scheduled'. When a schedule is complex, all component tasks must be temporally-bound. Schedule 2 Branching task A task that articulates the plan into an ordered set of tasks. A specialization of ending-task, aimed at sequencing events that end a plan execution without having reached its main-goal for a certain time, and can be considered with no chance of resurrecting the original plan execution. While 'abortion' depends on external causes, 'abandonment' depends on decisions. Abortion task An abstract merging task is a merging aimed at 'formally' joining the tasks that are direct successor to a case task. Differently from synchronization tasks, which are expected to be executed, abstract mergings only provide abstract boundaries to a task structure, because in a case task, only one action task is supposed to be executed. Abstract merging task An atomic task. Elementary task A control task that directly precedes both a case task and some other task.It specializes the branching task. Partly case task A loop task with a defined number -and possibly frequency- of iterations. Loop for A specialization of ending-task, aimed at sequencing events that end a plan execution having reached its main-goal. Completion task A beginning task is a control task that is the predecessor of all tasks defined in the plan. Beginning task A loop task, which specifies when a certain condition becomes true for a cyclical task to exit. Loop until Temporally bound task A deliberation task is a control task that sequences deliberation states (decisions taken after a case task execution). Deliberation task An abstract plan is a plan whose roles and tasks do not classify specific entities. They only specify classes of entities that can be included in a plan execution. This condition cannot be formalized in FOL, since we would like to express a condition by which an instance of an abstract plan specifies instances of plan components, but no instances of execution elements, e.g. that 'manager' classifies some (if any) instance of person, but not a specified (named) person. Abstract plan An ending task is a control task that has no successor tasks defined in the plan. Ending task A concurrent task is a task branched to a set of tasks executable concurrently -the sequenced perdurants can overlap-, which means that no deliberation task is performed in order to choose among them. A concurrent task has at least one successor synchronization task, which is aimed at waiting for the execution of all -except the optional ones- tasks direct successor to the concurrent -or any order, see below- one.The axioms cannot be expressed fully in OWL-DL (no value mapping available). Concurrency task A control task aimed at starting an activity. It is specialized either by a beginning task or a reactivation task. Activation task An any order task is a branching task that defines no order in the successor tasks. Itís another way of defining a bag task, because any temporal relation can be expected between any two perdurants sequenced by the tasks that are direct successor to the any order task. Any order task A saturated plan is a dul:Plan that cannot be executed twice, since it defines spatio-temporal parameters restricted to one value, e.g. one of its tasks classifies an event that is valued by a definite dul:TimeInterval and a definite dul:SpaceRegion Of course, in the case of maximal spatio-temporal regions, a saturated plan tends to approximate an abstract plan from the execution viewpoint, but these worst cases are unavoidable when dealing with maximality. Saturated plan A task for parallel concurrent activities. Parallel task is input of is output of has input has main goal A main goal can be defined as a goal that is part of a plan but not of one of its subplans. The characteristic axiom cannot be formalized in OWL-DL (it requires coreference). is main goal in has output iteration cardinality can be used to state in a task how many times an action should be repeated has iteration cardinality