Organizing Business Knowledge The Mit Process Handbook [Electronic resources] نسخه متنی

A.5 Alphabetic Class Reference

Parent Classes ENTITY

Attribute Descriptions

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  Component. The subactivities of the activity. For example, if the activity is 'Develop software', its Component may include 'Design software', 'Write code', and 'Debug software'. The field is inherited from ENTITY, but here it is restricted so that its values must all be ACTIVITY entities.



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  Precondition. The conditions that have to be satisfied at the Begin timepoint of the activity before it can get executed. For example, a precondition of the activity 'Run software'might state that the executable code must be available. Such conditions are expressed using PIF-SENTENCES.



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  Postcondition. The conditions that are true at the End timepoint of the activity. For example, a postcondition of the activity 'Run software'might be that a log file has been updated. Such conditions are expressed using PIF-SENTENCES.



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  Begin. The TIMEPOINT at which the activity begins.



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  End. The TIMEPOINT at which the activity ends.

In the PIF-CORE, the condition in the Precondition is to be true before the Begin timepoint of the ACTIVITY. Similarly, the condition in the Postcondition is to be true after the End timepoint of the ACTIVITY. This requirement may be relaxed later in PSV modules (cf. section A.6) to allow the precondition and the postcondition to be stated relative to other time points.

Many preconditions and postconditions can be expressed in PIF without using the Precondition and Postcondition attributes of ACTIVITY. For example, the USE relation between an activity A and an object O implies that one of A's preconditions is that R is available. In general, the Precondition and Postcondition attributes of ACTIVITY should only be used to express conditions that cannot be expressed any other way in PIF. Doing so will maximize the degree to which a process description can be shared with others.

Parent Classes RELATION

Attribute Descriptions

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  Activity. The activity whose status is being specified.



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  Status. The status being specified such as DELAYED and PENDING.



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  When. The timepoint at which the status of the activity is being specified.

Parent Classes OBJECT → ENTITY

Attribute Descriptions

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  Capability. Its possible values are SYMBOLS that represent the kinds of skills the agent is capable of providing. The symbols are supplied by the source language and simply preserved across translations by PIF. A PSV module may introduce a restricted set of symbol values.

An AGENT represents a person, group, or other entity (e.g., a computer program) that participates in a process. An AGENT is distinguished from other ENTITIES by what it is capable of doing or its skills.

Parent Classes RELATION → ENTITY

Attribute Descriptions

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  Preceding-Timepoint. The time point that is before the Succeeding Timepoint



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  Succeeding-Timepoint. The time point that is after the Preceding Timepoint.

BEFORE is a relation between TIMEPOINTS not between ACTIVITIES. A shorthand for a common example of the BEFORE relation is available via the SUCCESSOR relation.

Parent Classes RELATION → ENTITY

Attribute Descriptions

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  Activity. The activity that creates the object. The object is assumed to be created at some nondeterminate timepoint(s) between its Begin and its End timepoint inclusive.



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  Object. The object that the activity creates.

Parent Classes ACTIVITY → ENTITY

Attribute Descriptions

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  If. The condition being tested to decide which successor relations to follow. Such conditions are expressed using PIF-SENTENCES.



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  Then. The activity to follow if the condition in the If field holds (i.e., if the PIF-SENTENCE in the If field evaluates TRUE).



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  Else. The activity to follow if the condition in the If field does not hold (i.e., if the PIF-SENTENCE in the If field evaluates to FALSE).

A DECISION is a special kind of activity that represents conditional branching. If the PIF-SENTENCE in its If attribute is TRUE, the activity specified in its Then attribute follows. If not, the activity in its Else attribute follows.

Parent Classes None. ENTITY is the root of the PIF class hierarchy.

Attribute Descriptions

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  Name. The entity's name.



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  Documentation. A description of the entity.



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  Component. This attribute is used to specify an homogeneous aggregate of the type itself. For example, in an AGENT object, this attribute can be used to specify that the agent is in fact a group of subagents. In an ACTIVITY object this attribute is used to specify its subactivities that make up the activity. If one needs to specify a group of objects of different types, then one can do so by going up to an object of their common ancestor type and specify them in the Component attribute of this object. When interpreted as a relation, this relation holds between the entity and each value, not between the entity and the set of all the values.



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  Constraint. This attribute is used to specify any constraint that should be true of the other attribute values in the current entity (e.g., constraints on the variables).



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  User-Attribute. This attribute is used to store additional ad hoc attributes of an entity that are not part of its class definition. For example, a process modeling application might allow users to specify additional attributes for AGENT entities that are not included in AGENT's PIF definition—the user might want to add an attribute recording the AGENT's age, for example. Such additional attributes can be stored in the User-Attribute attribute, which all PIF entities inherit from ENTITY. Another common use is in the Partially Shared Views translation scheme that we propose for interchanging PIF files (see section A.6). Each value of User-Attribute is a list containing an attribute name and its value(s). For example, an OBJECT entity might have (User-Attribute (Color RED GREEN) (Weight 120)).

Parent Classes RELATION → ENTITY

Attribute Descriptions

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  Activity. The activity that modifies the object. The object is assumed to be modified at some nondeterminate timepoint(s) between its Begin and its End timepoint inclusive.



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  Object. The object that the activity modifies.

Parent Classes ENTITY

Attribute Descriptions No attribute.

An OBJECT is an entity that can be used, created, modified, or used in other relationships to an activity. This includes people (represented by the AGENT subclass in PIF), physical materials, time, and so forth. The PIF Working Group has discussed adding OBJECT attributes such as Consumable and Sharable, but so far no decision has been made on what attributes are appropriate.

Parent Classes RELATION → ENTITY

Attribute Descriptions

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  Actor. The object that performs the activity.



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  Activity. The activity that is performed. The actor is assumed to perform the activity at some nondeterminate timepoint(s) between its Begin and its End timepoint inclusive.

Parent Classes ENTITY

Attribute Descriptions No attribute.

RELATION entities have no attributes of their own. PIF uses it as an abstract parent class for more specific relation classes such as USES and PERFORMS.

Parent Classes RELATION → ENTITY

Attribute Descriptions

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  Preceding-Activity. The preceding activity.



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  Succeeding-Activity. The succeeding activity.

SUCCESSOR with the Preceding-Activity ACTIVITY-1 and the Succeeding-Activity ACTIVITY-2 is exactly the same as BEFORE with Preceding-Timepoint TP-1 and Succeeding-Timepoint TP-2, where TP-1 is the Begin timepoint of ACTIVITY-2 and TP-2 is the End timepoint of ACTIVITY-1. That is, the SUCCESSOR relation is true if the ACTIVITY-1 ends before the ACTIVITY-2 begins.

Parent Classes ENTITY

Attribute Descriptions No attribute.

TIMEPOINT represents a point in time. In PIF-CORE, it is used, for example, to specify the Begin and End times of an Activity or the Preceding and Succeeding time points of the BEFORE relation.

Parent Classes RELATION → ENTITY

Attribute Descriptions

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  Activity. The activity that uses the object from its Begin timepoint to its End timepoint. The USES relation is true from the Begin to the End timepoint of the activity. The object is assumed to be used at some nondeterminate timepoint(s) between its Begin and its End timepoint inclusive.



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  Object. The object that the activity uses.