POSC Specifications: Epicentre Version 3.0 | Logical Data Model |
A limit or restriction on the times at which two activities may occur in a specified schedule. The constraints may describe the future (and constrain two planned activities) or the past (implying the times of actual activities were constrained). For example, assembly could not start until the components were delivered.
- ref_schedule_constraint (M, K: ref_schedule_constraint(schedule_constraint)) (C138)
- The constraint kind, describing the logical condition of the constrained activity with respect to either the constraining activity or absolute time. Examples are: start of constrained activity leads the end of the constraining activity by relative time; start of constrained activity lags absolute time by relative time. Each schedule_constraint must be a kind of one ref_schedule_constraint.
- schedule (M, K: schedule(schedule_constraint))
- Gives the schedule that the schedule constraint is valid for. A schedule constraint is only valid for one schedule. Each schedule_constraint must constrain activities of one schedule.
- constrained_by (O, K: activity(constraint_for))
- This activity acts as a constraint, via the schedule constraint, upon the other activity related to this schedule constraint. Each schedule_constraint may defined as having as a constraint one activity.
- constraint_for (M, K: activity(constrained_by))
- Gives the activity that is constrained by this schedule constraint. Each schedule_constraint must have defined as constraining one activity.
- absolute_time (O: ndt_date_tod)
- A reference to a calendar date and clock time, constraining the time at which the constrained activity of the schedule constraint may be scheduled. The type of constraint using the absolute time value is given by the constraint kind.
- activity_duration (O: ndt_day_interval)
- The duration of the constrained activity of the schedule constraint. This may act as an upper limit, a lower limit or both. The limit type is specified by the constraint kind.
- description (O, I: ndt_comment) (C117)
- A remark or comment about the instance. Inherited from e_and_p_data.
- instance_create_date (O, I: ndt_date_tod) (C126)
- This is the date that this instance was created. This date is defined by the source if imported, or is the date the instance is created if a new instance. Inherited from e_and_p_data.
- instance_creator (O, I: ndt_identifier) (C126)
- This is the person, company or application that created this instance. This identifies the party responsible for loading this instance. Inherited from e_and_p_data.
- last_updated (O, I: ndt_date_tod) (C126)
- This is the date that this instance was last updated. This value should be updated when any part of this instance is altered (except for inverse relationships). Inherited from e_and_p_data.
- last_updated_by (O, I: ndt_identifier) (C126)
- This records the person or application making the update to this instance. Inherited from e_and_p_data.
- relative_time (O: ndt_day_interval)
- The time interval between the constrained activity and either the constraining activity or the absolute time for the schedule constraint. The role of the time interval is given by the constraint kind.
- source (O, I: ndt_identifier) (C126)
- The provider of this instance, which is usually a data provider for imported/purchased data. If this instance is provided by POSC, then this attribute must be "POSC". Inherited from e_and_p_data.
- data_collection (I, V: SET[0:?] data_collection_content(collection_part)) (C020)
- Indicates the data collections that include this instance of E and P data. Each schedule_constraint may be a member of one or more data_collection_content. Inherited from e_and_p_data.
- document_information_content (I, V: SET[0:?] document_information_content(e_and_p_data)) (C136)
- These are the document specification parts that include this data value and define its meaning within a document specification. Each use may define a different meaning, and many uses are allowed. Each schedule_constraint may be included in one or more document_information_content. Inherited from e_and_p_data.
- graphical_element (I, V: SET[0:?] graphical_element(depicted_object))
- Specifies one or more graphical elements which are depicting this data item. Each schedule_constraint may be depicted by one or more graphical_element. Inherited from e_and_p_data.
Local rules:
- Uniqueness Constraint
- ref_schedule_constraint, schedule, constrained_by, constraint_for
Supertype path(s):
Referenced in Diagrams:
Generated on Tue Jul 10 15:53:58 2001
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