Template:— change_relationship (chg_rel)
Context:— UK_Defence

Date: 2009/04/17 10:31:43
Revision: 1.2

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 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 UK_Defence Task Dependency using Activity_relationship.

This represents the relationship between a causal and consequential change.

Business perspective

The change relationship business object is used by those UK_Defence Data Exchange Specifications that require information about the relationships between changes.

Business object definition

Figure 1 — Graphical Representation for Business Object Change Relationship

Change Relationship :

This template encompasses the requirements of a UK_Defence Change Relationship.

The definition of a UK_Defence Change Relationship object is:

This information object represents the cause/effect relationship between two Changes. The record consists of the attributes for a change relationship; listed below.

Attribute name	Attribute description	Attribute type	Optionality
ID	This is the identifier of the change relationship. Currently the requirement for this is the subject of an issue.	Identifier	Mandatory
Causal Change	This is the reference to the Change that causes the Consequential Change to be initiated..	Change Definition	Mandatory
Consequential Change	This is the reference to the Change that is initiated by the Causal Change..	Change Definition	Mandatory

Table 1 — 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 "change_relationship". The text highlighted in blue shows the template parameters.

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

Input parameters

The following input parameters are defined for this template:

causal_change (Type= 'ENTITY (Activity)' )

This is the reference to the Change that causes the Consequential Change to be initiated

consequential_change (Type= 'ENTITY (Activity)' )

This is the reference to the Change that is initiated by the Causal Change.

Reference parameters

The following reference parameters are defined for this template:

act_rel(Type='ENTITY (Activity_relationship)')

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

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

%^target = $change_relationship.act_rel%

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

Uniqueness constraints

The following parameter combinations specify a uniqueness constraint:

Unique constraint: Unique change_relationship

Each instance of the entity (Activity_relationship) within the data set shall be uniquely identified by a combination of the following parameters on this template (change_relationship) namely: causal_change, consequential_change.
The instance is referenced by the following template parameter: act_rel.

There should be one causal and consequential change within the relationship.

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.

-- instantiate Activity_relationship
Activity_relationship
%^act_rel = Activity_relationship%
^act_rel.name = 'change_relationship'
^act_rel.description = '/IGNORE'
^act_rel.relating_activity -> @causal_change
^act_rel.related_activity -> @consequential_change

The following entities are instantiated with attributes as specified:

Entity in path	Value	Inherited from
Activity_relationship.name	'change_relationship'	—
Activity_relationship.description	'/IGNORE'	—

Instance diagrams

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

/change_relationship(causal_change='@1', consequential_change='@60')/

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

Figure 4 — Entities instantiated by 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:

/change_relationship(causal_change='@1', consequential_change='@60')/

Figure 5 — Instantiation of change_relationship template

Characterizations

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