Template:— property_change_relationship (prop_chg_rel)
Context:— UK_Defence

Date: 2010/03/15 14:46:04
Revision: 1.3

Cover Contents Description Bus. perspective Bus. obj.Model diags.Input params.Ref. params.Instantiation path Instance diags.Characterizations Issues in situ

This section specifies the template property_change_relationship.

NOTE The template has been defined in the context of UK_Defence. Refer to the business context for details of related templates.

NOTE An explanation of a template and the associated instantiation path is provided in the Template overview section.

Description

This template describes how to represent a relationship between two properties where one is a subsequent value to the prior value.

This is required where for example, the increments/decrements in the value of a property need to be able to be calculated from the two referenced properties.

Business perspective

The Property Change Relationship business object is used by those UK_Defence Data Exchange Specifications to represent a relationship between two properties where one is a subsequent value to the prior value.

Business object definition

Figure 1 — Graphical Representation for Business Object Property Change Relationship

Property Change Relationship

The definition of a Property Change Relationship object is: This information object represents information about the relationship between two properties where one is a subsequent value to the prior value.

Attribute name	Attribute description	Attribute type	Optionality
ID	This is the identifier of the property increment relationship.	Identifier	Mandatory
Prior value	This is the reference to the property that contains the prior value which can be used for calculating the increment or decrement in the property.	Property	Mandatory
Subsequent value	This is the reference to the property that contains the subsequent value which can be used for calculating the increment or decrement in the property.	Property	Mandatory

Table 1 — Property Change Relationship attribute details

Model diagrams

The EXPRESS-G diagram in Figure 2 shows the templates and EXPRESS entities that are required to represent the template "property_change_relationship". The text highlighted in blue shows the template parameters.

Figure 2 — An EXPRESS-G representation of the Information model for property_change_relationship

The graphic for the template to be used in other EXPRESS-G diagrams is shown in Figure 3 below.

Figure 3 — The graphical representation of the property_change_relationship template

Input parameters

The following input parameters are defined for this template:

ID (Type='STRING')

This is the identifier of the property increment relationship.

source_organization (Type='STRING')

The organization that created the associated identifier. Additionally a Person or Information System could be defined when either of these are the source; see Identifier template characterizations

prior_value (Type= 'ENTITY (Assigned_property)' )

This is the reference to the property that contains the prior value which can be used for calculating the increment or decrement in the property.

subsequent_value (Type= 'ENTITY (Assigned_property)' )

This is the reference to the property that contains the subsequent value which can be used for calculating the increment or decrement in the property.

Reference parameters

The following reference parameters are defined for this template:

prop_chg_rel(Type='ENTITY (Representation_relationship)')

Allow the Representation_relationship entity instantiated in this path to be referenced when this template is used.

Note: The Representation_relationship entity can be referenced in a template path by:

%^target = $property_change_relationship.prop_chg_rel%

where target is the parameter to which the Representation_relationship is bound.

Uniqueness constraints

The following parameter combinations specify a uniqueness constraint:

Unique constraint: Unique property change relationship

Each instance of the entity (Representation_relationship) within the data set shall be uniquely identified by a combination of the following parameters on this template (property_change_relationship) namely: ID, prior_value, subsequent_value.
The instance is referenced by the following template parameter: prop_chg_rel.

Instantiation path

The instantiation path shown below specifies the entities that are to be instantiated by the template.

A description of templates and the syntax for the instantiation path is provided in the Templates Help/Information section.

-- Create the Selected_item entity
Selected_item
Selected_item.id = '/IGNORE'
Selected_item.name = '/IGNORE'
Selected_item.description = '/IGNORE'
%^sel_item = Selected_item%
%^prop_chg_rel = $property_value_relationship.rep_rel%
/identifier(
    ID=@ID,
    source_organization=@source_organization,
    type='Organization_identification_code',
    items=^sel_item)/

-- create the property_value_relationship entity
/property_value_relationship(
    rel_type='Succession_relationship',
    rel_type_ecl_id='urn:plcs:rdl:std',
    relating=@prior_value,
    related=@subsequent_value)/

-- [optional Classification_assignment]
Classification_assignment
Classification_assignment.role = '/IGNORE'
Classification_assignment.items -> ^prop_chg_rel
Classification_assignment.assigned_class -> ^sel_item

The following entities are instantiated with attributes as specified:

Entity in path	Value	Inherited from
Selected_item.id	'/IGNORE'	Class.id
Selected_item.name	'/IGNORE'	Class.name
Selected_item.description	'/IGNORE'	Class.description
Classification_assignment.role	'/IGNORE'	—

Instance diagrams

The instance diagram in Figure 4 shows an example of the EXPRESS entities and templates that are instantiated by the template:

/property_change_relationship(ID='PCR123', source_organization='UK_Defence', prior_value='@28', subsequent_value='@1')/

(an illustration of the consolidated property_change_relationship template is shown in Figure 5 below.)

Figure 4 — Entities instantiated by property_change_relationship template

The instance diagram in Figure 5 shows the graphic symbol for the template that is to be used in other instance diagrams. The example template is:

/property_change_relationship(ID='PCR123', source_organization='UK_Defence', prior_value='@28', subsequent_value='@1')/

Figure 5 — Instantiation of property_change_relationship template

Characterizations

No common characterizations of the template property_change_relationship have been identified. However, the ISO 10303-239 EXPRESS model may enable other assignments to the entities instantiated by the template.