IfcTaskTime是IFC4中新增的实体。
| Item | SPF | XML | Change | Description |
|---|---|---|---|---|
| IFC2x3 to IFC4 | ||||
| IfcTaskTime | ADDED | |||
| IFC4 Addendum 1 | ||||
| IfcTaskTime | ||||
| IsCritical | MODIFIED | Type changed from BOOLEAN to IfcBoolean | ||
IfcTaskTime捕获与时间相关的任务信息，包括不同类型（实际或计划）的开始和结束时间。
所有给定的值都应由应用程序提供；IFC模式不处理任务时间值之间的依赖关系。也没有一致性检查通过where规则来保证时间值的有意义填充。因此，应用程序负责提供合理的值，如果应用程序收到任务时间，则必须自己进行一致性检查。
IfcTaskTime还提供了一种通用机制，用于区分用户给定的时间值和从用户给定的时间值派生的时间值以及其他约束（如工作日历和分配的资源）。
Attribute definitions
| # | Attribute | Type | Cardinality | Description | C |
|---|---|---|---|---|---|
| 4 | DurationType | IfcTaskDurationEnum | [0:1] | Enables to specify the type of duration values for ScheduleDuration, ActualDuration and RemainingTime. The duration type is either work time or elapsed time. | X |
| 5 | ScheduleDuration | IfcDuration | [0:1] | The amount of time which is scheduled for completion of a task. The value might be measured or somehow calculated, which is defined by ScheduleDataOrigin. The value is either given as elapsed time or work time, which is defined by DurationType.
NOTE Scheduled Duration may be calculated as the time from scheduled start date to scheduled finish date. |
X |
| 6 | ScheduleStart | IfcDateTime | [0:1] | The date on which a task is scheduled to be started. The value might be measured or somehow calculated, which is defined by ScheduleDataOrigin.
NOTE The scheduled start date must be greater than or equal to the earliest start date. |
X |
| 7 | ScheduleFinish | IfcDateTime | [0:1] | The date on which a task is scheduled to be finished. The value might be measured or somehow calculated, which is defined by ScheduleDataOrigin.
NOTE The scheduled finish date must be greater than or equal to the earliest finish date. |
X |
| 8 | EarlyStart | IfcDateTime | [0:1] | The earliest date on which a task can be started. It is a calculated value. | X |
| 9 | EarlyFinish | IfcDateTime | [0:1] | The earliest date on which a task can be finished. It is a calculated value. | X |
| 10 | LateStart | IfcDateTime | [0:1] | The latest date on which a task can be started. It is a calculated value. | X |
| 11 | LateFinish | IfcDateTime | [0:1] | The latest date on which a task can be finished. It is a calculated value. | X |
| 12 | FreeFloat | IfcDuration | [0:1] | 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. It is a calculated elapsed time value. | X |
| 13 | TotalFloat | IfcDuration | [0:1] | The difference between the duration available to carry out a task and the scheduled duration of the task. It is a calculated elapsed time value.
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. |
X |
| 14 | IsCritical | IfcBoolean | [0:1] | 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. |
X |
| 15 | StatusTime | IfcDateTime | [0:1] | The date or time at which the status of the tasks within the schedule is analyzed. | X |
| 16 | ActualDuration | IfcDuration | [0:1] | The actual duration of the task. It is a measured value. The value is either given as elapsed time or work time, which is defined by DurationType. | X |
| 17 | ActualStart | IfcDateTime | [0:1] | The date on which a task is actually started. It is a measured value.
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. |
X |
| 18 | ActualFinish | IfcDateTime | [0:1] | The date on which a task is actually finished. | X |
| 19 | RemainingTime | IfcDuration | [0:1] | The amount of time remaining to complete a task. It is a predicted value. The value is either given as elapsed time or work time, which is defined by DurationType.
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. |
X |
| 20 | Completion | IfcPositiveRatioMeasure | [0:1] | The extent of completion expressed as a ratio or percentage. It is a measured value. | X |
Inherited definitions from supertypes
Entity inheritance
