IfcScheduleTimeControl
Definition from buildingSMART International: The IfcScheduleTimeControl captures the time-related information about a process including the different types (i.e. actual, or scheduled) of starting and ending times, duration, float times, etc.
HISTORY: Existing class in R1.5.1, Renamed to IfcScheduleTimeControl in R2.0.
Use Definitions
Scheduled and actual durations of a task and all float times should be derived within an application from relevant start and finish times that are also attributes of this class. Note that they are not directly derived within the IFC specification at this stage due to the differences in data type between time measures date/time selections.
The critical nature of an IfcScheduleTimeControl may also be derived within an application by comparing relevant start and finish date/time selections but is not derived within the IFC specification at this stage.
EXPRESS specification:
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| ActualStart | : | The date on which a task is actually started. NOTE: The scheduled start date must be greater than or equal to the earliest start date. No constraint is applied to the actual start date with respect to the scheduled start date since a task may be started earlier than had originally been scheduled if circumstances allow. |
| EarlyStart | : | The earliest date on which a task can be started. |
| LateStart | : | The latest date on which a task can be started. |
| ScheduleStart | : | The date on which a task is scheduled to be started. NOTE: The scheduled start date must be greater than or equal to the earliest start date. |
| ActualFinish | : | The date on which a task is actually finished. |
| EarlyFinish | : | The earliest date on which a task can be finished. |
| LateFinish | : | The latest date on which a task can be finished. |
| ScheduleFinish | : | The date on which a task is scheduled to be finished. NOTE: The scheduled finish date must be greater than or equal to the earliest finish date. |
| ScheduleDuration | : | The amount of time which is scheduled for completion of a task. NOTE: Scheduled Duration may be calculated as the time from scheduled start date to scheduled finish date. |
| ActualDuration | : | The actual duration of the task. |
| RemainingTime | : | The amount of time remaining to complete a task. NOTE: The time remaining in which to complete a task may be determined both for tasks which have not yet started and those which have. Remaining time for a task not yet started has the same value as the scheduled duration. For a task already started, remaining time is calculated as the difference between the scheduled finish and the point of analysis. |
| FreeFloat | : | The amount of time during which the start or finish of a task may be varied without any effect on the overall programme of work. |
| TotalFloat | : | The difference between the duration available to carry out a task and the scheduled duration of the task.
NOTE: Total Float time may be calculated as being the difference between the scheduled duration of a task and the available duration from earliest start to latest finish. Float time may be either positive, zero or negative. Where it is zero or negative, the task becomes critical. |
| IsCritical | : | A flag which identifies whether a scheduled task is a critical item within the programme. NOTE: A task becomes critical when the float time becomes zero or negative. |
| StatusTime | : | The date or time at which the status of the tasks within the schedule is analyzed. |
| StartFloat | : | The difference between the late start and early start of a task. Start float measures how long an task's start can be delayed and still not have an impact on the overall duration of a schedule. |
| FinishFloat | : | The difference between the late finish and early finish of a task. Finish float measures how long an task's finish can be delayed and still not have an impact on the overall duration of a schedule. |
| Completion | : | The extent of completion expressed as a ratio or percentage. |
| ScheduleTimeControlAssigned | : | The assigned schedule time control in the relationship. |
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