Entity schedule_constraint

• 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.

Attribute                                 Flags   Data Type

From association:
   data_collection                        IV      set[0 .. N] of (data_collection)

                                          Indicates the data collections that include this
                                          instance of E and P data. 

   graphical_element                      IV      set[0 .. N] of (graphical_element)

                                          Specifies one or more graphical elements which
                                          are depicting this data item. 


absolute_time                             N       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                         N       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                                       ndt_comment

                                          A description of the schedule constraint. 

ref_schedule_constraint                   MU      ref_schedule_constraint

                                          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. 

relative_time                             N       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.

schedule                                  MU      schedule

                                          Gives the schedule that the schedule constraint
                                          is valid for. A schedule constraint is only valid
                                          for one schedule. 

constrained_by                            U       activity

                                          This activity acts as a constraint, via the schedule
                                          constraint, upon the other activity related to
                                          this schedule constraint. 

constraint_for                            MU      activity

                                          Gives the activity that is constrained by this
                                          schedule constraint. 

End of entity schedule_constraint

M - mandatory, U - unique, I - inherited, V - inverse, N - named type