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Description: A textual description, or glossary, associated with the ObjectSchematic. Any descriptive information that does not logically fit into the otherfields in the document may be placed here.The next step in Object Schematic development is to describe each object state andcharacterize the state transitions. To accomplish this, the analyst will perform thefollowing tasks:1.Identify the defining characteristics for each object state.2.Identify the conditions for leaving each state.3.Identify the criteria for entering each state.4.Identify special conditions for enabling an object in the state to attempt atransition.1245.Identify the possible transitions between states.6.Identify the activities that cause, allow, or are caused by each transition.Develop Elaborations for Object States, Objects, Junctions, and LinksThe results of the first two activities are recorded on the object state elaboration formfor each affected state.
The results of the third and fourth activities are documented onthe transition link elaboration form. The results of the last three activities determine theschematic layout. The structure and content of these elaboration forms closely parallelthose associated with Process Schematic elements. Examples of these forms are providedin the following few pages (See Figures 4-11 through 4-14).The object state elaboration document is used to capture the elaborations of the objectstates that participate in the state transitions depicted in an Object Schematic. An objectstate elaboration document is constructed for every object state represented in the ObjectSchematic.
In addition to enabling a detailed characterization of a state, the object stateelaboration document form carries information about state and exit conditions, asdiscussed in Section 3, IDEF3 Process Description Language. The object stateelaboration document is shown in Figure 4-11.125DATE:USED AT: ANALYST:PROJECT:1 2 3 4 5 6 7 8 9 10NOTES:ObjectStateNo.REV:WORKINGDRAFTRECOMMENDEDRELEASEDREVIEWER:DATE:Object State Name:Label:OSTransitions From Object State(s):Transitions To Object State(s):Facts:Constraints:State Conditions:Exit Conditions:Other:Description:CONTEXT-SETTINGREFERENCE:ITEM DESCRIBED:FORM TYPE:Object StateElaborationFigure 4-11Object State Elaboration FormThe following list contains a description of the fields that appear on an object stateelaboration form:1.Object State No.: A unique identification number for the object state, prefacedby the letters “OS.”2.Object State Name: The name of the object state.4.Label: The Object Schematic name, some part of the name, or an abbreviationused for convenience when displayed in an IDEF3 graphical element (e.g., whendisplayed in a referent).5.Transitions From Object State(s): The object state(s) from which the objecttransitions.6.Transitions To Object State(s): The object state(s) to which the objecttransitions.7.Facts: Facts that hold about objects in this state.1268.9.Constraints: Constraints on objects in this state.
In particular, three types ofconstraints are listed:a.State Conditions – Conditions that are individually necessary for an objectto be in the state in question.b.Exit Conditions – Sufficient conditions for an object to no longer be in thestate in question.c.Other – Additional constraints of interest.Description: A textual description, or glossary, associated with the ObjectState. Any descriptive information that does not logically fit into any of theother fields in the document may be placed here.The transition link elaboration document is used to capture the elaborations of thetransition links in an Object Schematic. A transition link elaboration document isconstructed for every transition link represented in the Object Schematic.
A transitionlink itself only indicates what object states can transition to which others. Hence, itselaboration consists only of the transition conditions for instances of its source state in anattempt to begin a transition that brings about an instance of its destination state and ofthe entry conditions that objects arising from its source state must meet to enter thedestination state.
In addition to containing this information, the transition linkelaboration document also contains a unique transition link number for the link as well asthe name of the Object Schematic that contains it (in the context setting reference field).The transition link elaboration document is shown in Figure 4-12.127DATE:USED AT: ANALYST:PROJECT:1 2 3 4 5 6 7 8 9 10NOTES:LinkNo.Path No.REV:WORKINGDRAFTRECOMMENDEDRELEASEDSource:REVIEWER:DATE:Destination:TLObjects:Facts:Constraints:Transition Conditions:Entry Conditions:Other:Description:CONTEXT-SETTINGREFERENCE:ITEM DESCRIBED:FORM TYPE:Transition LinkElaborationFigure 4-12Transition Link Elaboration FormThe fields that appear on the transition link elaboration form include:1.Link No.: A unique identification number for the transition link, prefaced bythe letters “TL.”2.Path No.: A link path number, comprised of the Link No.
and a unique integer,separated by a period. For example, given a transition link TL1 that separatesinto three alternative paths following a junction, the path link numbers would beTL1.1, TL1.2, and TL1.3.3.Source: Name of the source IDEF3 element (e.g., Object State) indicated by alink.4.Destination: Name of the destination IDEF3 element (e.g., Object State) of therelation indicated by the link.5.Objects: All significant objects (types or instances) that participate in therelation represented by the transition link.1286.Facts: Noteworthy, nonconstraining facts involving the objects that participatein the relationship represented by the transition link.7.Constraints: Constraints on objects in this state.
In particular, three types ofconstraints are listed:8.a.Transition Conditions – Conditions that are individually necessary andjointly sufficient for there to be an attempted transition from the source tothe destination.b.Entry Conditions – Sufficient conditions for an object to enter the stategiven an object (possibly different) in the source state of that link that hasmet the relevant transition conditions.c.Other – Additional constraints of interest.Description: The glossary associated with the transition link. Any descriptiveinformation that does not logically fit into any of the other fields in thedocument may be placed here.As appropriate, objects, facts, and constraints uniquely associated with a particularlink path will be identified.At this point, it may be useful to identify other objects and relations that can provideadditional context-setting information relevant to the transition.
Two elaboration formsare provided to assist with this task: the object elaboration document and the relationlink elaboration document.The object elaboration document is used to further characterize context-setting objectsincluded in the Transition Schematic which are not directly involved in the focustransition. An example form for the object elaboration document is provided in Figure 413.129DATE:USED AT: ANALYST:PROJECT:NOTES:ObjectStateNo.1 2 3 4 5 6 7 8 9 10REV:WORKINGDRAFTRECOMMENDEDRELEASEDREVIEWER:DATE:Object Name:Label:OFacts:Constraints:Description:CONTEXT-SETTINGREFERENCE:ITEM DESCRIBED:FORM TYPE:Object ElaborationFigure 4-13Object Elaboration FormThe following list describes the contents of each field on the object elaborationdocument.1.Object State No.: An object number, prefaced by the letter “O” (for Object),that uniquely identifies the Object.2.Object Name: This section contains the Object Name.3.Label: This section contains the Object Label (i.e., the Object Name, some partof the Name, or an abbreviation).4.Facts: This field lists facts about instances of the Object.5.Constraints: This field lists constraints on the Object, i.e., facts about whatmust hold in all instances of the Object.6.Description: This field contains a glossary entry (textual description) for theObject.
Typically, the glossary entry provides a textual recount of theinformation already in the object, fact, and constraint lists.130The relation link elaboration document is used to further characterize the relationsbetween objects and object states in an Object Schematic (other than the “transitions-to”relation). Figure 4-14 illustrates an example relation link elaboration form serving thispurpose.DATE:USED AT: ANALYST:PROJECT:NOTES:LinkNo.1 2 3 4 5 6 7 8 9 10REV:WORKINGDRAFTRECOMMENDEDRELEASEDREVIEWER:DATE:Relation Name:Relation Type (first-order, second-order):RLObjects and Object States involved (i.e., arguments):Facts:Constraints:Description:CONTEXT-SETTINGREFERENCE:ITEM DESCRIBED:FORM TYPE:Relation LinkElaborationFigure 4-14Relation Link Elaboration FormThe fields contained on the relation link elaboration form are as follows:1.Link No.: A link number, prefaced by the letters “RL” (for relational link), thatuniquely identifies the relation link within the description.2.Relation Name: This section contains the Relation name.3.Relation Type: A description of the number of places and order of the relation(e.g., 2-place, first-order).4.Objects and Object States involved (i.e., arguments): A list of the Object(s)and Object State(s) involved in the relation.5.Facts: Noteworthy nonconstraining facts involving the objects that participatein the relationship represented by the relation link.1316.Constraints: Noteworthy constraints that hold between the participatingobject(s) and object state(s) or between some of their constituent objects.7.Description: The glossary associated with the relation link.
Any descriptiveinformation that does not logically fit into the other fields in the document maybe placed here.Incrementally Refine and Validate IDEF3 Process DescriptionsMotivationThe leverage of IDEF3 for description capture is particularly noticeable whenvalidation activities are undertaken. Conventional process modeling often force users togloss over gaps in the description or simplify facts with idealizations.
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