Capability (C086):— representing

This capability is used in conjunction with a product as a structure of components that are sub-assemblies, parts or slots. A slot represents the position in which a part is or can be attached to an assembly, when it is necessary to record the history of usage of that slot. It defines the concepts required to build the relationships which provide the structure for representing slots. A part is a type of product which represents a design.

EXAMPLE A ship has four engines each attached at a mounting point in an engine room. These mounting points each has an associated slot, which are identified as slot 1, slot 2, slot 3, and slot 4. In normal usage only two main engines are are operating, the remaining two provide an operating enhancement if all four operate or a backup for the two main engines. The attached engines are tracked against their respective slots. If the ship does not have all of its engines installed, one or more slots are empty. An empty slot is subject to a different maintenance regime than an installed engine.

EXAMPLE The pylon mounting on an aircraft wing is used to carry a radar, or fuel tank. The mounting has an associated slot. The fatigue life of the mounting will be determined differently depending on what is fitted at the slot and the duration of operating in that configuration which could be based on flying hours, landings, the calendar or some other measure.

EXAMPLE A fast jet aircraft has two engines. These engines are removable and interchangeable between individual aircraft. A slot represents each installation position for an engine so as to ensure that an accurate record is maintained of which engines fly in which pairing on which aircraft for how many hours.

Information model overview

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

These versions correspond to the same PLCS approach to lifecycle management that are afforded to Parts, Product_as_planned and Product_as_realized described earlier in the busines section. The distinction between design, planned and realized products is also provided in capability C045: representing_product_as_individual (shortly to become representing_product_as_individual).

In some cases there may be a requirement to mix these lifecycle definitions as some parts may be treated as products in their own right. For example, a pre-fabricated slot may already exist which can be planned for during the design stage.

This capability covers both the representation of slots and the relationships between versions of slots. The process for generating these are described in the following sections.

Representation of Slots

Step 2; The identification of the Slot is represented through the use of the Identification_assignment entity which is applied to each of the entities involved in representing the Slot. This only shows part of the identification method since this is described in the dependent capability, C001: assigning_identifiers.

Step 3; The context of a Slot is represented through the use of the entity View_definition_context. These are necessary for the unambiguous referencing a Slot which further complements the identification in step 2.

The classification representation which uses instances of external _class has a source, which is for PLCS purposes going to be provided in a reference data library (RDL). This is shown below.

Representing Versions of Slots

NOTE Both slot and slot design are shown having the same date/time for the assignments. It is likely the the slot is defined at the time of representing the design.

NOTE Both slot and slot as planned are shown having different date/time for the assignments. It is likely that the date of design is earlier than that of the process plan.

NOTE Both slot and slot as realized are shown having different date/time for the assignments. It is likely that the date of design and planned versions is earlier than that of the realized/as-built.

NOTE The same structure of elements are employed to represent both slot_design and slot_as_realized. These are not shown here. See capabiliity representing_slots for more details.

NOTE A complete assembly is not shown here - only the use of one contruct (promissory_usage) typically used in the representation of an assembly. Next_assembly_usage is another popular building block.

NOTE The slot in this case forms part of a simple assembly (through promissory_usage) and at the same time identifies the parent in the assembly as the product upon which the slot sits. A slot may be defined at any level in the assembly - not just the top level as shown here.

Representing a Part in a Slot

Representing a part or product that occupies a slot makes use of the Product_in_attachment_slot relationship which links a Attachment_slot_definition with a Product. The following figure shows the representation of a Soundblaster PC card occupying the slot defined which is part of the PC assembly. It also shows the use of the Attachment_slot_on_product which identifies the top-level product on which the Attachment_slot sits.

Management of a Slot through life

In cases where it is necessary to identify specific versions, the identification assignment of each should be specified. The figure below shows this.

The Referencing of Individual Slots

Characterization of model

The identification of the Slot is represented through the use of the Identification_assignment entity which is applied to each of the entities involved in representing the Slot. The identification assignment is subsequently classified through the Classification_assignment entity. For a Slot, the classification assigned should be a "slot_identification_code". For a Attachment_slot_version the classification assigned should be a "Version_code". For a Attachment_slot_definition, the classification assigned should be a "Identification_code". The class assigned through this mechanism is normally represented as an external_class as defined within an external_class_library. This is described more fully in the capability C010: assigning_reference_data. The identification assignment also has a responsible organization or person assigned to indicate the relevant owner using the entity Organization_or_person_in_organization_assignment. This is explained in greater depth in the capability referencing_person_organization

Error C1: Capability referencing_person_organization not in dex_index.xml
. Additionally, a date and / or date and time may optionally also be assigned to the identification assignment using the entity Date_or_date_time_assignment. This is described in greater depth in the capability C036: assigning_date_time. This process of identification is described in the dependent capability, C001: assigning_identifiers.

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.

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

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

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

%^target = $referencing_slot.ext_class%

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

Identification_assignment

-- Mark the Identification_assignment entity as
-- referable when this template is used by binding it to the reference
-- parameter id_assgn
%^id_assgn = Identification_assignment%

Error P8: the template referencing_slot does not have a parameter name [id].
Identification_assignment.identifier = @id
Identification_assignment.role = '/IGNORE'
Identification_assignment.description = '/NULL'

Error P4: the template referencing_slot does not have a parameter name [items].
Identification_assignment.items -> @items

-- provide the role of the identification by classifying the Identification_assignment
/assigning_reference_data(
    items=^id_assgn,
    class_name=@id_class_name,
    ecl_id=@id_ecl_id)/

Error t3: the template referencing_slot does not have a parameter name [id_class_name]. Parameters are: class_name items class_name ecl_id

Error t3: the template referencing_slot does not have a parameter name [id_ecl_id]. Parameters are: class_name items class_name ecl_id

-- assign an organization to the identifier and classify it as 'Owner_of'
/assigning_organization(
    items=^id_assgn,
    org_id=@org_id,
    org_id_class_name=@org_id_class_name,
    org_id_ecl_id=@org_id_ecl_id,
    org_assgn_class_name='Owner_of',
    org_assgn_ecl_id='http://www.plcsinc.org/plcs-proposed')/

Error t3: the template referencing_slot does not have a parameter name [org_id]. Parameters are: class_name items class_name ecl_id

Error t3: the template referencing_slot does not have a parameter name [org_id_class_name]. Parameters are: class_name items class_name ecl_id

Error t3: the template referencing_slot does not have a parameter name [org_id_ecl_id]. Parameters are: class_name items class_name ecl_id

The instance model in STEP ASCII exchange file format (ISO 10303 Part 21 syntax) is:


          #1 = TASK_METHOD($,$,$,$,());
          #2 = EXTERNAL_CLASS('/IGNORE','Safety_critical',$,#3);
          #3 = EXTERNAL_CLASS_LIBRARY('urn:plcs:rdl:std',$);
          #4 = CLASSIFICATION_ASSIGNMENT(#2,(#1),'/IGNORE');

The instance model in STEP XML exchange file format (ISO 10303 Part 28 ed.2 syntax) is:

The following characterizations may apply:

Characterization Assigning date

NOTE this characterization is optional.

The date when the Work_order and the Directed_activity was issued can be represented by assigning a date (using the relationship Date_or_date_time_assignment) to the Work_order and the Directed_activity using the assigning_calendar_date template with the Date_time being classified as a type of "Date actual release" (urn:plcs:rdl:std:Date actual release).

NOTE The assignment of dates is described the capability C036: assigning_date_time.

Related capabilities

Dependent capabilities

This capability "representing slots" is dependent on the following capabilities:

Business overview