PDM-UG: Activity decomposition
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This page belongs to the PDM Usage Guide.
The work being directed as part of a work order (the ‘work definition’) may be further decomposed into sub-activities. These sub-activities are related to the directed_action through an action_relationship (or a chain of such action_relationships) with name 'decomposition'.
When many requests using different solutions are incorporated by a single work order, the directed_action representing the complete work definition should be decomposed in sub-activities for which each appropriate method is indicated.
The items that are affected by a specific sub-activity, e.g., as input or output, may be identified. If the directed_action representing the ‘work definition’ is broken down in separate sub-activities, it is recommended that this top level work definition be associated through applied_action_assignment to all input and output items that are affected by the sub-activities.
Status information specifying the level of completion of each activity may be specified. Additional administrative information such as persons, organizations, and date and time related information as well as approval information can also be attached to these activities.
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The Instance Model: EXPRESS entities and attributes
The EXPRESS entities and attributes used to support the requirements to represent activity decomposition information are illustrated in Diagram 69 below. The corresponding STEP exchange file encoding is given in Example 69.
Diagram 69: Activity Decomposition Instance Diagram
Executed action
The executed_action entity represents a type of action that has been identified as a task that has to be carried out. The activity may be simply identified, partially completed, or completed. An executed_action may have status information associated with it through action_status to indicate the level of completeness.
An executed_action refers to an associated action_method that describes the procedure selected to carry out the activity and a description of the results. An executed_action is related to the items that it affects through the applied_action_assignment entity. This is used to identify the inputs and outputs (i.e., results) of the executed_action.
An executed_action may be related directly to a work order as a decomposition of the work definition (directed_action). When work order decomposition is a requirement, the executed_action is then indirectly related (via the directed_action reference from an action_directive) to the work requests that are addressed by the described activity. By reference to an action_method that is identified as a potential solution to the addressed work_request(s), the executed_action indicates which specific procedure or potential solution for a work_request it has adopted.
Attributes
- The name attribute specifies the word or common name used to refer to the action.
- The description attribute specifies additional information about the action.
- The chosen_method attribute specifies the action_method that defines the procedure selected to carry out the action and a description of the results of the action.
- The id attribute is derived, and may store the unique identifier for an executed_action.
| ENTITY executed_action | Attribute Population | Remarks |
| name | type: label = text | |
| description | type: text = string | OPTIONAL |
| chosen_method | type: entity = action_method | |
| id | DERIVEd attribute type: identifier = string | exactly one id may be associated via the entity id_attribute |
===Preprocessor Recommendations=== Preprocessor Recommendations: An executed_action that is not of its subtype directed_action may be identified as sub-activity in the activity decomposition structure of a directed_action that represents the 'work definition' for a work order. In other words, an executed_action may be referenced as the related_action in an action_relationship with name 'decomposition' that has a relating_action (potentially through a chain of intermediate action_relationships), which is a directed_action.
It is recommended that an executed_action have an associated status to describe its level of completion, represented by exactly one action_status which references the executed_action as the assigned_action (see Action status).
The executed_action entity may have an identifier associated with it through the entity id_attribute and its attribute_value attribute.
===Postprocessor Recommendations=== There are no specific postprocessor recommendations.
===Related Entities=== An executed_action may be referenced by the following entities:
- action_relationship to associate a directed_action and an executed_action or two executed_actions, e.g., to define their decomposition relationship, i.e., one action as part of the other, or to describe their dependencies.
- applied_action_assignment to identify the items that are affected by the executed_action.
- applied_approval_assignment to associate approval information related to an executed_action. See Approval for guidance in creating the approval constructs.
- applied_date_assignment (or applied_date_and_time_assignment) to associate date (and time) information to an executed_action. See Date and Time for guidance in creating the date and time constructs.
- applied_ organization_assignment (or applied_person_and_organization_assignment) to associate organization (and person) information to an executed_action. See Organization and Person for guidance in creating the organization and person constructs. A recommended value for the name attribute of the person_and_organization_role is 'requestor'.
- applied_contract_assignment to identify that an executed_action is subject of the assigned contract.
- applied_document_reference to associate a document with the action_method.
Action status
The action_status entity represents the association of a status with an executed_action (or its subtype directed_action) to specify its level of completion.
Attributes
- The status attribute specifies the level of completion of the associated executed_action or directed_action.
- The assigned_action attribute specifies the executed_action the status is specified for.
| ENTITY action_status | Attribute Population | Remarks |
| status | type: label = text | |
| assigned_action | type: entity = executed_action |
===Preprocessor Recommendations=== An executed_action shall have at most one associated action_status, which references the executed_action as the assigned_action.
===Postprocessor Recommendations=== There are no specific postprocessor recommendations.
===Related Entities=== There are no specific related entities.
Action relationship
An action_relationship establishes a relationship between two activities represented by directed_action or executed_action instances. The meaning of the action_relationship is given by its name attribute. An action_relationship is used to define an activity as sub-activity, i.e., as part of the decomposition of some higher-level activity. The action_relationship may also be used to express some dependency such as sequential relationship in time, between two activity objects.
In the context of work management, all defined activities are related either directly or indirectly to a work order. Definition of the complete work to be done, represented by a directed_action, is directly related to a work order. An executed_action defining a sub-activity of the complete work definition is indirectly related to the work order, i.e., related to that directed_action through the action_relationship.
If a directed_action or an executed_action is further decomposed into sub-activities, this shall be a complete decomposition of the higher level activity, i.e., all sub-activities belonging to the same decomposition level together shall completely define the activity on the next higher level.
If the executed_actions defined as sub-activities of a directed_action contain references to items that are either input or output, then these items shall also be explicitly related to the top-level directed_action.
Attributes
- The name attribute specifies the meaning of the relationship.
- The description attribute specifies additional information text that characterizes the action_relationship.
- The relating_action specifies the first action, which is related by the action_relationship. The relating_action usually identifies the activity the definition of the related_action is based on, e.g., derived from or dependent on. The semantics of this attribute should be defined by the name attribute.
- The related_action specifies the second action related by the action_relationship. The related_action usually identifies the action, which is based on the definition of the relating_action. The semantics of this attribute should be defined by the name attribute.
| ENTITY action_relationship | Attribute Population | Remarks |
| name | type: label = string | |
| description | type: text = string | OPTIONAL |
| relating_action | type: entity = action | |
| related_action | type: entity = action |
===Preprocessor Recommendations=== The name attribute is used to specify the type of the action_relationship. The value ’decomposition’ for the name attribute should be used to indicate that the related_action is one of potentially more components into which the relating_action is broken down. Where applicable, the following additional values may be used: 'derivation' to indicate that the related_action is derived from the relating_action; ’precedence’ to indicate that the related_action has higher priority than the relating_action; ’sequence’ to indicate that the relating_action shall be completed before the related_action starts.
===Postprocessor Recommendations=== There are no specific postprocessor recommendations.
===Related Entities=== There are no specific related entities.
The Instance Model: STEP exchange file format (ISO10303 Part 21 syntax)
#2=VERSIONED_ACTION_REQUEST('var id2', '0001', 'technical improvement', 'description of var id2, 0001');
#5=ACTION_REQUEST_STATUS('issued', #2);
#9=ACTION_METHOD('technical improvement method 1', $, 'effects of technical improvement method 1', '$');
#10=ACTION_METHOD('technical improvement method 2', $, 'effects of technical improvement method 2', '$');
#14=ACTION_REQUEST_SOLUTION(#9, #2);
#15=ACTION_REQUEST_SOLUTION(#10, #2);
#16=APPLICATION_CONTEXT('mechanical design');
#100=PRODUCT_RELATED_PRODUCT_CATEGORY('part', '', (#440));
#220=PRODUCT_CONTEXT('', #16, '');
#230=PRODUCT_DEFINITION_CONTEXT('part definition', #16, 'design');
#340=PRODUCT_DEFINITION_CONTEXT_ROLE('part definition type', $);
#350=PRODUCT_DEFINITION_CONTEXT('assembly definition', #16, '');
#440=PRODUCT('s1', 'sleeve assembly', $, (#220));
#450=PRODUCT_DEFINITION_FORMATION('A', '', #440);
#460=PRODUCT_DEFINITION('sv1', 'design view on sleeve assembly', #450, #230);
#520=PRODUCT_DEFINITION_CONTEXT_ASSOCIATION(#460, #350, #340);
#531=APPLIED_ACTION_REQUEST_ASSIGNMENT(#2, (#450));
#534=ACTION_DIRECTIVE('wo id2', 'design change', 'results of analysis of var id2', 'comment 2', (#2));
#536=DIRECTED_ACTION('design change', $, #10, #534);
#537=ACTION_METHOD('activity method 1', $, 'effects of activity method 1', 'objectives of activity method 1');
#538=PRODUCT_DEFINITION_FORMATION('B', '', #440);
#539=PRODUCT_DEFINITION('sv3', 'analysis view on sleeve assembly', #538, #230);
#541=APPLIED_ACTION_ASSIGNMENT(#536, (#538, #539, #561));
#548=EXECUTED_ACTION('define requirements', $, #537);
#549=EXECUTED_ACTION('detailed design', $, #551);
#550=EXECUTED_ACTION('analysis and simulation', $, #552);
#551=ACTION_METHOD('activity method 2', $, 'effects of activity method 2', 'objectives of activity method 2');
#552=ACTION_METHOD('activity method 3', $, 'effects of activity method 3', 'objectives of activity method 3');
#553=ACTION_RELATIONSHIP('decomposition', $, #536, #548);
#554=ACTION_RELATIONSHIP('decomposition', $, #536, #549);
#555=ACTION_RELATIONSHIP('decomposition', $, #536, #550);
#556=ACTION_RELATIONSHIP('sequence', $, #548, #549);
#557=ACTION_RELATIONSHIP('sequence', $, #549, #550);
#558=ACTION_STATUS('completed', #548);
#559=ACTION_STATUS('completed', #549);
#560=ACTION_STATUS('in-work', #536);
#561=PRODUCT_DEFINITION('sv2', 'design view on sleeve assembly', #538, #230);
#562=APPLIED_ACTION_ASSIGNMENT(#549, (#561));
#563=APPLIED_ACTION_ASSIGNMENT(#550, (#539));
#564=ACTION_STATUS('in-work', #550);
