IfcCostResource (成本资源)
IfcCostResource
IfcCostResource提供了识别成本值的方法。
成本值以适用于该值类型的度量单位指定对应用于对象的金额有影响的金额或值。成本价值可以有一个适用的日期，该日期可以用来提供价格波动的基础，或者以其他方式确定成本价值何时适用。
每个成本值可能有一个单位基础，用于确定应如何确定对象的总价值。当一个项目的单位数量的值被识别时，这是相关的。
单个成本值可以根据一组组成值的值来定义，也可以被标识为其他值的组成部分。这是通过断言作为应用值组件容器的应用值关系来实现的。
Types
1 IfcArithmeticOperatorEnum
2 IfcAppliedValueSelect
Entities
1 IfcAppliedValue
2 IfcCostValue
3 IfcCurrencyRelationship
类型：
1 IfcArithmeticOperatorEnum (运算符枚举类型)
IfcArithmeticOperatorEnum指定关系所隐含的算术运算的形式。
Enumeration definition
| Constant | Description |
|---|---|
| ADD | |
| DIVIDE | |
| MULTIPLY | |
| SUBTRACT |
2 IfcAppliedValueSelect (应用值选择类型)
IfcAppliedValueSelect定义要在公式中计算的值。
类型使用如下：
●IfcValue：使用项目默认单位的常量值。
●IfcMeasureWithUnit：使用指定单位的常量值。
●IfcReference：对象属性上引用的值。
对于成本价值，以下指导适用：
●IfcMeasureWithUnit允许指定值的实际数字和表示值的货币。
●选择IfcMonetaryMeasure只允许指定值，货币由全局上下文设置。
●选择IfcRatioMeasure时，假设金额是一个百分比或其他实数。请注意，如果金额通常指定为-20%，则需要将此数字转换为0.8的乘数
Enumeration definition
| Constant | Description |
|---|---|
| IfcMeasureWithUnit | |
| IfcValue | |
| IfcReference |
实体：
1 IfcAppliedValue (应用实体)
此实体捕获由公式计算的值，附加条件包括单位基础、有效日期范围和分类。
IfcAppliedValue的范围由AppliedValue属性确定，该属性可以定义为IfcMeasureWithUnit或IfcMonetaryMeasure，也可以通过IfcAppliedValueSelect类型定义为IfcRatioMeasure。
可选地，IfcAppliedValue可以有一个适用的日期。这是为了确定使用价值的相关日期。它可以是模型中设置值的日期，也可以是值变得可操作的之前或将来的日期。类似地，IfcAppliedValue可能有一个“固定截止日期”。这是为了确定价值停止使用的日期。
IfcAppliedValue的实例可以声明一个单元基。这被定义为IfcMeasureWithUnit，用于确定用于应用的单位值的范围。假设在断言此属性时，给IfcAppliedValue的值是单位数量的值。这不是在模式中强制执行的，因此需要在应用程序中进行控制。
应用的值可以从文档（如价目表）中引用。IfcAppliedValue（或其子类型）的一个或多个出现之间的关系是通过使用IfcExternalReferenceRelationship实现的，其中文档提供IfcExternalReferenceRelationship.relatingextereference和值出现是IfcExternalReferenceRelationship.RelatedResourceObjects。
| # | Attribute | Type | Cardinality | Description | C |
|---|---|---|---|---|---|
| 1 | Name | IfcLabel | [0:1] | A name or additional clarification given to a cost value. | X |
| 2 | Description | IfcText | [0:1] | The description that may apply additional information about a cost value. | X |
| 3 | AppliedValue | IfcAppliedValueSelect | [0:1] | The extent or quantity or amount of an applied value. | X |
| 4 | UnitBasis | IfcMeasureWithUnit | [0:1] | The number and unit of measure on which the unit cost is based. Note: As well as the normally expected units of measure such as length, area, volume etc., costs may be based on units of measure which need to be defined e.g. sack, drum, pallet, item etc. Unit costs may be based on quantities greater (or lesser) than a unitary value of the basis measure. For instance, timber may have a unit cost rate per X meters where X > 1; similarly for cable, piping and many other items. The basis number may be either an integer or a real value. Note: This attribute should be asserted for all circumstances where the cost to be applied is per unit quantity. It may be asserted even for circumstances where an item price is used, in which case the unit cost basis should be by item (or equivalent definition). | X |
| 5 | ApplicableDate | IfcDate | [0:1] | The date on or from which an applied value is applicable. | X |
| 6 | FixedUntilDate | IfcDate | [0:1] | The date until which applied value is applicable. | X |
| 7 | Category | IfcLabel | [0:1] | Specification of the type of cost used.
NOTE There are many possible types of cost value that may be identified. Whilst there is a broad understanding of the meaning of names that may be assigned to different types of costs, there is no general standard for naming cost types nor are there any broadly defined classifications. To allow for any type of cost value, the IfcLabel datatype is assigned.In the absence of any well defined standard, it is recommended that local agreements should be made to define allowable and understandable cost value types within a project or region. |
X |
| 8 | Condition | IfcLabel | [0:1] | The condition under which a cost value applies. For example, within the context of a bid submission, this may refer to an option that may or may not be elected. | X |
| 9 | ArithmeticOperator | IfcArithmeticOperatorEnum | [0:1] | The arithmetic operator applied to component values. | X |
| 10 | Components | IfcAppliedValue | L[1:?] | Optional component values from which AppliedValue is calculated. | X |
| HasExternalReference | IfcExternalReferenceRelationship @RelatedResourceObjects |
S[0:?] | Reference to an external reference, e.g. library, classification, or document information, that is associated to the IfcAppliedValue. | X |
2 IfcCostValue (成本实体)
IfcCostValue是一个货币量或影响一个货币量的值。
IfcCostValue的每个实例也可以有一个类别。有许多可能的成本价值类型可以确定。虽然人们对可分配给不同类型费用的名称的含义有着广泛的理解，但没有为费用类型命名的一般标准，也没有任何广义的分类。
下面定义了一些可能应用于“类别”属性的成本类别：
- Annual rate of return
- Bonus
- Bulk purchase rebate
- Contract
- Consultancy
- Delivery
- Estimated cost
- Hire
- Installation
- Interest rate
- Labor
- Lease
- List price
- Maintenance
- Material
- Overhead
- Postage and packing
- Profit
- Purchase
- Rental
- Repair
- Replacement
- Sale
- Small quantity surcharge
- Spares
- Storage
- Sub-Contract
- Trade discount
- Transportation
- Waste allowance
- Whole life
3 IfcCurrencyRelationship (货币关系实体)
IfcCurrencyRelationship定义在特定时间适用于两种指定货币的汇率，并由特定来源发布。
如果可能需要将一种货币的IfcCostValue引用到另一种货币的IfcCostValue，则使用IfcCurrencyRelationship。它考虑到货币汇率可能因要求记录所用货币汇率的日期和时间以及公布汇率的来源而有所不同。可能有许多来源和不同的货币兑换策略（即期汇率，以固定汇率远期购买货币）。
货币兑换的源被定义为包含名称和URL的IfcLibraryInformation的实例。
| # | Attribute | Type | Cardinality | Description | C |
|---|---|---|---|---|---|
| 3 | RelatingMonetaryUnit | IfcMonetaryUnit | [1:1] | The monetary unit from which an exchange is derived. For instance, in the case of a conversion from GBP to USD, the relating monetary unit is GBP. | X |
| 4 | RelatedMonetaryUnit | IfcMonetaryUnit | [1:1] | The monetary unit to which an exchange results. For instance, in the case of a conversion from GBP to USD, the related monetary unit is USD. | X |
| 5 | ExchangeRate | IfcPositiveRatioMeasure | [1:1] | The currently agreed ratio of the amount of a related monetary unit that is equivalent to a unit amount of the relating monetary unit in a currency relationship. For instance, in the case of a conversion from GBP to USD, the value of the exchange rate may be 1.486 (USD) : 1 (GBP). | X |
| 6 | RateDateTime | IfcDateTime | [0:1] | The date and time at which an exchange rate applies. | X |
| 7 | RateSource | IfcLibraryInformation | [0:1] | The source from which an exchange rate is obtained. | X |
