Capability (C095):— assigning

Capability (C095):— assigning_descriptor

Date: 2007/06/22 12:22:09
Revision: 1.10

Cover Contents Intro.Overview Info. model Templates Capabilities.Ref. data Issues

Business overview

This section provides a business level overview of this capability.

A descriptor is information about an object, provided as text which don't have to comply with any rules.

EXAMPLE Examples of descriptors are:

Descriptions;
Notes;
Comments;
Remarks.

An object may have zero, one or many descriptors assigned to it.

Over time, an object might be assigned with more than one descriptor of the same type. These may be distinguished by the person or the organization that provided the descriptor. In situations where a person or an organization may provide more than one descriptor of the same type, these may be distinguished by the usage of an assigned date.

Information model overview

This section provides an overview of the information model that supports this capability.

Descriptive information is applied using Document, and Document_assignment.

Figure 1 below shows the main entities and key capabilities used.

Figure 1 — ExpressG diagram, Main entities and capabilities used to assign a descriptor

Text representation and classification

The text that represents the descriptor shall be represented as a string using the Document inherited description attribute.

The descriptor is assigned to the entity under consideration using Document_assignment.

Type of descriptor is determined by classification through the usage of reference data using the C010: assigning_reference_data capability. The classification shall be assigned to the Document_assignment entity.

In a data exchange, the Document shall be classified as "Descriptor" (urn:plcs:rdl:std:Descriptor).

An example is given in Figure 2 which shows the representation of a description assigned to a Part. The Document_assignment is classified as "Description" (urn:plcs:rdl:std:Description), and the Document is classified as "Descriptor" (urn:plcs:rdl:std:Descriptor).

Figure 2 — Assigning a description to a Part

NOTE See the C002: representing_parts for information on how to represent a part.

Model Characterization

This section specifies how the information model can be further characterized by the assignment of additional information such as dates, approvals and people or organizations.

The following characterizations may apply.

Characterization: Assigning an organization to the Document_assignment (Optional)

The organization that assigned the descriptor may be determined through the usage of the C094: assigning_organization capability. The assigning Organization should be assigned to the Document_assignment entity in the role of "Owner of" (urn:plcs:rdl:std:Owner of).

This characterization should be used in situation where the same type of descriptor may be assigned the same entity instance by several parties. An example is mutliple descriptions assigned to a Part provided by the Original Equipment Manufacturer, Supplier and User Oragnization respectively.

An example is given in Figure 3 which shows the representation of an assigning Organization. The 'BikeHire Limited' organization is assigned to the description in the role of "Owner of" (urn:plcs:rdl:std:Owner of).

Figure 3 — Representation of the Organization that assigned the description

The Document_assignment may be further characterized through the assignment of a Calendar_date . This characterization is recommended in situations where the same organization may assign multiple descriptors of the same type to the same entity instance. The calender date should be assigned in the role of "Date actual creation" (urn:plcs:rdl:std:Date actual creation).

An example is given in Figure 4 which shows the representation of the date when the 'BikeHire Limited' assigned the description. The date is assigned in the role of "Date actual creation" (urn:plcs:rdl:std:Date actual creation).

Figure 4 — Representation of the Date when the 'BikeHire Limited' assigned the description to the Part

Additional usage guidance

This section describes additional usage guidance where the PLCS data model provides abilities closely related to the scope covered by this capability.

Description vs usage of properties

Never use the capabilities C076: assigning_product_properties, C078: assigning_resource_properties, C077: assigning_process_properties, together with C080: representing_properties_textually (i.e. the String_representation_item entity) to represent textual descriptions, notes, comments, remarks etc.

Capability templates

The following sections define a set of templates for the capability, where a template is a specification of a set of entities that need to be instantiated to represent a given set of information.

Template: assigning_descriptor (Short name: asg_descr)

This section specifies the template assigning_descriptor.

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

Description

This template describes the assignment of descriptors to entities within a data set. The meaning of the assignment is provided by classification. The template excludes the usage of defined characterizations.

NOTE A descriptor is a generic term for textual descriptions, remarks, notes etc.

Model diagrams

The EXPRESS-G diagram in Figure 1 shows the templates and EXPRESS entities that are required to represent the template "assigning_descriptor". The text highlighted in blue shows the template parameters.

Figure 1 — Attribute values set by the template 'assigning_descriptor'.

The graphic for the template to be used in other EXPRESS-G diagrams is shown in Figure 2 below.

Figure 2 — Graphical representations of the template 'assigning_descriptor'.

Input parameters

The following input parameters are defined for this template:

descr (Type='STRING')

The text being assigned as a descriptor.

class_name (Default=Description,Type='CLASS')

The name of the class (External_class) being used to determine type of descriptor.

The following classes and their sub-classes can be used:

classifications: "Descriptor_assignment" (urn:plcs:rdl:std:Descriptor_assignment)

ecl_id (Default=urn:plcs:rdl:std,Type='URN')

The id of the External_class_library that stores the class.

is_assigned_to (Type= 'SELECT (documented_element_select)' )

The entity to which the Document_assignment is assigned.

Reference parameters

The following reference parameters are defined for this template:

descr_asg(Type='ENTITY (Document_assignment)')

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

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

%^target = $assigning_descriptor.descr_asg%

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

descr(Type='ENTITY (Document)')

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

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

%^target = $assigning_descriptor.descr%

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

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 Reading Capability Templates help section.

Document_assignment

-- Mark the Document_assignment entity as referable when this template is used.
-- In other words, bind the Document_assignment instance to the reference
-- parameter descr_asg
%^descr_asg = Document_assignment%
Document_assignment.role = '/IGNORE'
Document_assignment.is_assigned_to -> @is_assigned_to

-- Provide the role of the descriptor by classifying the Document_assignment
/assigning_reference_data(
    items=^descr_asg,
    class_name=@class_name,
    ecl_id=@ecl_id)/

-- Mark the Document entity as referable when this template is used.
-- In other words, bind the Document instance to the reference parameter descr
%^descr = Document%
Document_assignment.assigned_document -> Document
Document.id = '/IGNORE'
Document.name = '/IGNORE'
Document.description = @descr

-- Define the role of the Document as descriptor, by classification
/assigning_reference_data(
    items=^descr,
    class_name='Descriptor',
    ecl_id='urn:plcs:rdl:std')/

The following entities are instantiated with attributes as specified:

Entity in path	Value	Inherited from
Document_assignment.role	'/IGNORE'	—
Document.id	'/IGNORE'	Product.id
Document.name	'/IGNORE'	Product.name
Document.description	@descr	Product.description

Instance diagrams

The instance diagram in Figure 3 shows an example of the EXPRESS entities and templates that are instantiated by the template:

/assigning_descriptor(items='#1', descr='The frame can be regarded as the skeleton of your bike. It structural design is such that it can withstand a great deal of stress.', class_name='Description', ecl_id='urn:plcs:rdl:std')/

(an illustration of the consolidated assigning_descriptor template is shown in Figure 4 below.)

Note that two instances of the template assigning_reference_data are used in the diagram. Namely:

@4 /assigning_reference_data(items='#2', class_name='Descriptor', ecl_id='urn:plcs:rdl:std')/

and

@8 /assigning_reference_data(items='#3', class_name='Description', ecl_id='urn:plcs:rdl:std')/

Figure 3 — Instance diagram instantiated by the template example

The instance diagram in Figure 4 shows the graphic symbol for the template that is to be used in other instance diagrams. The example template is:

Figure 4 — Invocation of template - graphical presentation

Characterizations

The following section details how the assigning_descriptor template can be optionally characterized by assigning other constructs to it. These are characterizations commonly applied to the template. The ISO 10303-239 EXPRESS model may enable other assignments to the entities instantiated by the template.

The EXPRESS-G diagram in Figure 5 shows the possible characterizations of the template "assigning_descriptor".

Figure 5 — Examples of optional characterizations of a descriptor

The following characterizations may apply:

Characterization Assigning date time

NOTE this characterization is optional.

Dates may be associated with the assignment of a descriptor (reference parameter ^descr_asg) by using the template assigning_time. For example, the date and time when a descriptor was assigned may enable simple version management.

Characterization Assigning organization

NOTE this characterization is optional.

Organizations may be associated with the assignment of a descriptor (reference parameter ^descr_asg) by using the template assigning_organization. This enables multiple descriptors to assigned to the same object, but from different perspectives.

Related capabilities

This capability "Assigning descriptive information" is related to the following capabilities:

Dependent capabilities

This capability "Assigning descriptive information" is dependent on the following capabilities:

Model reference data

The following classes of reference data are required for this capability:

Descriptor(urn:plcs:rdl:std:Descriptor)

document that represents information about an object, provided as text which don't have to comply with any rules. Note: This class is valid for PLCS ed 1. Its usage will replaced by an explicit Description class in PLCS ed 2.