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Calculated Attributes

A calculated attribute is an attribute whose value is determined by a value template that includes a formula of functions and arguments and/or static text. A value template can also give access to information from references, compare data between objects, round numbers, modify text, and many other options, which are defined in the Calculated Attribute Functions section of the System Setup / Super User Guide here.

The foundation for a calculated attribute is a functional programming language very similar to the language used for defining functions in Excel. Calculated attributes are a special type of attributes whose values are not written in the database, but are calculated on the fly, based on other data in the system.

Both description attributes and specification attributes can be set as calculated attributes, and calculated attribute values can be used in Business Rules as any other attribute values.

When in workbench, calculated attributes are created by going to System Setup and clicking on the desired attribute. Then on the Attribute tab, click into the Calculated field, and select 'Yes' or 'No'. In Web UI this can be set on the Attribute Management screen. For information about Web UI, see the Calculated Attributes in Web UI section of the Web User Interfaces documentation here.

When an attribute is set as calculated, a Value template field displays. Functions added to the value template perform predefined actions on the argument(s) that are supplied. Arguments are placeholders for data (like an attribute ID or text that should be appended to a value).

For example, the following functions and arguments are included in the workbench image below:

• The 'concatenate' function takes a comma-delimited list of arguments. In this example, the three arguments are: prodval('Domestic Distribution ID'), "-", and prodval('International Distribution ID').
• The 'prodval' function takes an argument of an attribute ID and retrieves the value of the attribute identified. In this example, the two attribute IDs are: 'Domestic Distribution ID' and 'International Distribution ID'.

Note: The functions ‘prodval’ and ‘value’ act the same in fetching the attribute values in STEP.

• Assuming that the 'Domestic Distribution ID' value is 1234 and the 'International Distribution ID' value is 5678, the result of this Value template would be 1234-5678.

When a calculated attribute uses the validation base type of Embedded Number, Fraction, Integer, Number, or Numeric Text, a Unit template field displays. This field can hold a static Unit ID and/or an expression that evaluates to a Unit ID.

Differences Between Calculated Attributes and Standard Attributes

• The base validity that is assigned to a calculated attribute only takes effect when the calculated value is manually overridden. It is up to the formula in the calculation to control syntax of the resolved value, including any numeric min / max constraints, or the maximum length of text. A calculated value may in fact violate the settings in the validity. But if a calculated attribute is given the base validity of Integer with minimum and maximum values, then any override to the calculated value must conform to that validity.
• The dimension dependency of an attribute that is designated as Calculated is only relevant when an override has been entered. A calculated attribute may reference attribute values, or reference objects that are dimension dependent, so the result of a calculated attribute is not constrained by the dimension dependency set on the attribute itself, but an override to the calculated value must respect the dimension dependency.
• Multi-valued attributes and attributes with LOV validation cannot be set as calculated.
• An attribute with 'Calculated = Yes' should also have 'Mandatory = No' since the actual value is not maintained in the database.
• Values of calculated attributes are not available using Search since the value does not exist until the user views the object or the object is exported.
• There is a performance penalty whenever the values are to be calculated. Complex calculations affect the time it takes to load editors and export objects.
• When exporting calculated values in STEPXML files using cross-context mode, STEP will attempt to perform some optimization to avoid repetitive calculations per context. In this scenario, the following limitations exist:

1. None of the attributes used in the calculation can be dimension dependent.

2. There must be no iterations in the calculation that involve any kind of references or child products. Only attribute values that are directly on the selected object (or, if a product, an inherited value from a higher level) are allowed.

3. The calculated attribute cannot make use of an attribute value that is itself a calculated attribute.

If these criteria are met, then the system will calculate the value once and will export that value for each of the selected contexts. This can result in a reduction of the time to create the exported STEPXML file.

If these criteria are not met, then the calculation will be performed per context, which can increase the time to create the exported STEPXML file.

• Due to potential performance penalties, it is possible to disable the calculated attributes in workbench by going to View > Disable calculated values.

• In the Export Manager it is possible to choose whether or not Calculated Attributes should be resolved during export.

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