PDM-UG: Alias Identification
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This page belongs to the PDM Usage Guide.
An alias identification is a mechanism to associate an object with an additional identifier that is used to identify the object of interest in a different context, either in another organization, or in some other context. The alias identification mechanism shall not be used to alias supplied parts. See Supplied Part Identification.
The scope of the alias identification shall be specified either by the description of the associated identification_role or – if the scope is defined by an organization – with help of an applied_organization_assignment. The scope of an alias defines the context in which the id specified via applied_identification_assignment.assigned_id overrides the original id. A scenario might be that an object has an id in the context of the organization assigned in the role 'id owner' as a primary id and other ids defined via aliases that are valid in the context of some other organizations.
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The Instance Model: EXPRESS entities and attributes
The structure of the alias assignment is illustrated in Diagram 52. The applied_identification_assignment #1 implements the alias via pointing to the to be aliased objects via applied_identification_assignment.items. The alias is represented in the attribute applied_identification_assignment.assigned_id. To mark the applied_identification_assignment as an alias, an instance of identification_role with name = 'alias' is attached to it.
Diagram 52: Alias Identification Instance Diagram
The following table list the objects to which aliases can be assigned in the PDM Schema:
| Entity type | purpose of usage as aliased item applied_identification_assignment.items) |
| approval_status | allows an alias for the name for the status of acceptance, i.e., approval_status.name |
| document_file | allows an alias for the id of a digital or physical file, i.e., document_file.id |
| organization | allows an alias for organization.id |
| product_definition | allows an alias identification for product_definition.id. This capability can be used for instances of product_definition that model document representations as well as for production_definitions that represent views on parts |
| product_definition_formation | allows an alias identification for product_definition_formation.id. This capability can be used for instances of product_definition_formation that model document versions as well as for production_definition_formations that represent versions of parts |
| product | allows an alias identification for product.id. This capability can be used for instances of product that model documents as well as for instances of the entity product that represent parts. See Supplied Part Identification |
| shape_aspect_relationship | allows an alias identification for shape_aspect_ relationship.id. This capability can be used for instances of shape_aspects that model portions of a part as well as for instances of the entity shape_aspect_relationship that represent complete parts. |
applied_identification_assignment
This entity is a subtype of the entity identification_assignment. It allows the actual assignment of an identification_assignment entity to product data, in this case to a document_file entity representing an external file.
Attributes
- The assigned_id provides the identification string that is assigned to the objects listed in the items attribute.
- The role references an instance of identification_role that defines the role of the assignment. In the context here this role has the name 'alias'.
- The items attribute is used to reference the associated external file.
| ENTITY applied_identification_assignment | Attribute Population | Remarks | |
| assigned_id | type: identifier = string | ||
| role | type: entity = identification_role | ||
| items | type : entity = |
===Preprocessor Recommendations=== For each applied_identification_assignment used as an alias identification an identification_role with name, 'alias' must be used.
===Postprocessor Recommendations=== None specified.
===Related Entities=== If the scope of an alias is an organization, this scope can be specified by using an applied_organization_assignment that points to the applied_identification_assignment, which represents the alias.
identification_role
This entity defines a role for an identification_assignment and a description of that role. In the scope of the alias concept the identification_role has to be labeled 'alias'.
Attributes
- The name is the label by which the identification_role is known.
- The description is an optional text that characterizes the identification_role.
| ENTITY identification_role | Attribute Population | Remarks |
| name | type: label = string 'version' | must be instantiated as 'alias' |
| description | type: text = string | OPTIONAL |
===Preprocessor Recommendations=== The description attribute can be used to specify the applicability of an alias – if not specified by an organizational scope. An example for such would be a alias that is used internally in one specific system. '
===Postprocessor Recommendations=== None specified.
===Related Entities=== The entity identification_role describes the role of an applied_identification_assignment. In the context of alias definition this role has to be named 'alias'.
applied_organization_assignment
This entity is a subtype of organization_assignment, allowing the representation of the assignment of an organization to some product data.
Attributes
- The assigned_organization is the organization which is to be associated with the product data.
- The role attribute specifies the purpose of the association of the organization_assignment with product data. In the context of using this entity for alias identification the role is 'alias scope.
- The items attribute is a reference to the product data to which the organization is being assigned.
| ENTITY applied_organization_assignment | Attribute Population | Remarks |
| assigned_organization | type: entity = organization | |
| role | type: entity = organization_role | must be 'alias scope' in the given scope |
| items | type: entity (defined by organization_item_select) | SET[1:?] |
===Preprocessor Recommendations=== For defining an organizational scope of an alias assignment the applied_organization_assignment shall have a role 'alias scope'.
===Postprocessor Recommendations=== None specified.
Related Entities
- applied_date_assignment and applied_date_time_assignment to specify the assignment of an organization together with a date.
The Instance Model: STEP exchange file format (ISO10303 Part 21 syntax)
ISO-10303-21;
HEADER;
FILE_DESCRIPTION((''),'2;1');
FILE_NAME('', '20.08.1999, 13:19:42', (''), (''), '', '', '');
FILE_SCHEMA(('PDM_SCHEMA {1.2}'));
ENDSEC;
DATA;
/* The entities in the following section describe product data and */
/* organizational data as described in other chapters of the PDM */
/* usage guide */
#10 = PRODUCT_CATEGORY_RELATIONSHIP('', $, #20, #30);
#20 = PRODUCT_RELATED_PRODUCT_CATEGORY('Part', '', (#40));
#30 = PRODUCT_RELATED_PRODUCT_CATEGORY('Detail', $, (#40));
#40 = PRODUCT('p1', 'part 1', '', (#60));
#50 = PRODUCT_RELATED_PRODUCT_CATEGORY('part', '', (#40));
#60 = PRODUCT_CONTEXT('', #70, '');
#70 = APPLICATION_CONTEXT('');
#80 = APPLICATION_PROTOCOL_DEFINITION('version 1.2', 'pdm_schema', 2000, #70);
#90 = PRODUCT_DEFINITION_FORMATION('1', '', #40);
#100 = PRODUCT_DEFINITION('v1', 'view_on_part_1', #90, #110);
#110 = PRODUCT_DEFINITION_CONTEXT('part definition', #70, '');
#120 = PRODUCT_DEFINITION_CONTEXT_ASSOCIATION(#100, $, #130);
#130 = PRODUCT_DEFINITION_CONTEXT_ROLE('', $);
#140 = ORGANIZATION('org1', 'My organization', 'company');
#190 = ORGANIZATIONAL_ADDRESS('', '', '', '', 'ducktown', '', '', '', '', '', '', '', (#140), 'postal address');
#200 = APPLIED_ORGANIZATION_ASSIGNMENT(#140, #210, (#40));
#210 = ORGANIZATION_ROLE('id owner');
/*entities #150 to #185 express that the id of organization #140 */
/* is 'xyz_org' inside organization #185 */
#150 = APPLIED_IDENTIFICATION_ASSIGNMENT('xyz_org', #180, (#140));
#160 = APPLIED_ORGANIZATION_ASSIGNMENT(#185, #170, (#150));
#170 = ORGANIZATION_ROLE('alias scope');
#180 = IDENTIFICATION_ROLE('alias', 'alias for org1');
#185 = ORGANIZATION('org2', 'My second organization', 'company');
/* Entities #220 to #240 define that the id 'v1' of the part view #100 */
/* is aliased with the id 'v_external_1' inside the organization #140 */
#220 = APPLIED_IDENTIFICATION_ASSIGNMENT('v_external_1', #240, (#100));
#230 = APPLIED_ORGANIZATION_ASSIGNMENT(#140, #235, (#220));
#235 = ORGANIZATION_ROLE('alias scope');
#240 = IDENTIFICATION_ROLE('alias', 'alias for view id');
/* Entities #250 to ##270 define that the information related to the */
/* part view #100 has the status 'approved' */
#250 = APPROVAL(#270, '');
#260 = APPLIED_APPROVAL_ASSIGNMENT(#250, (#100));
#270 = APPROVAL_STATUS('approved');
/* Entities #280, #290 define 'accepted' as an alias for the approval */
/* status 'approved' */
#280 = APPLIED_IDENTIFICATION_ASSIGNMENT('accepted', #290, (#270));
#290 = IDENTIFICATION_ROLE('alias', 'alias for approval status - approved -');
ENDSEC;
END-ISO-10303-21;
