Value

Definition of Value

Definition Last Updated 17-Dec-2015 12:51

Relevant meanings of value include:

  • A value, an answer to a question concerning a characteristic or attribute of an entity of the kind “What is the [attribute name] of [entity name]?” such as, “What is the Colour of Snow?”, where “What is the [attribute name]…” means “What value does [attribute name] currently have?”
  • The value as the worth of something: an assessment of something’s price or desirability according to a particular rule;
  • To value something, to ascertain its value or to state that its value ranks high (directly or indirectly according to a rule)

A value is not limited to being a single thing, number or otherwise; values may also be ranges (as limits or distributions) or more general objects such as sets.

Scope

Value is a defined term of Enterprise Architecture. Value is a defined term of Business Architecture.

Discussion

Article Last Updated 17-Dec-2015 12:51

Value is an especially ambiguous term. It may mean either the specific result of an observation (or inference, such as a calculation) of a characteristic of something or the subjective worth – goodness or badness – of something.

In English, there is an important distinction between something having a value and something being of value.

Characteristics have specific values; states are defined and distinguished by specific characteristics having specific values, and particular states are of worth as a consequence of a relationship between the values of characteristics and reference values expressed implicitly or explicitly in criteria.

Value on its own is often used to refer to benefits; even though something might be worth less than it cost and so have a negative net value, when used without qualification value is positive.

Benefits are outcomes that have specific qualitative, subjective, worth. When the questions “What is the benefit of X?” or “What is the (business) value of X?” are asked (especially in the context of business analysis), subjective secondary attributes are implied and the analyst will relate value propositions such as “More applications processed per year is better” to the ability of X to process more applications.

In order to manage the complexity of determining business value, nominal worth may be expressed with respect to changes to indicators given for the Balanced Score Card and specific worth may be stated by quantifying the change.

For completeness, and to distinguish usage, we note in passing the UML concept of tagged values.

Just like a Class, a Stereotype1UML Modeling Language (OMG UML), v2.5, §12.3.3.4 pdf here says, “A Stereotype is a limited kind of metaclass that cannot be used by itself, but must always be used in conjunction with one of the metaclasses it extends.” i.e. it is a named set of characteristics predefined for convenient reuse which can be added to some other set of characteristics to characterise something. may have Properties, which have traditionally been referred to as Tag Definitions. When a Stereotype is applied to a model element, the values of the Properties have traditionally been referred to as tagged values.2UML Modeling Language (OMG UML), v2.5, §12.3.3.4 pdf here.[original emphasis]

UML’s Tag Definition and Tagged Values are not the same as Tags and their Values as defined here.

Examples

General – Gertrude is a Very Tall Giraffe

For example, adult giraffes (as a type) may typically be 5-6m tall; some specific giraffe called Gertrude may have an observable attribute called Height whose value is eight metres.

This height, according to the rule for giraffe tallness, If Height ≥ 7m Then Tallness = Very Tall, results in the attribution of the tag Tallness with value Very Tall to Gertrude, which would then render into English as Gertrude is very tall for a Giraffe.

Attribute: Colour – Value: Red

Note that the definition of red and the determination of redness may be problematic unless the context is well defined.

For example, in the case of tomatoes, which are typically either red, green or (occasionally) yellow, to say that the tomato is red is to say something quite specific about that tomato – probably that it is ripe.

In the case of a font colour, red may be a predefined value that can be applied by using some control in an application; however, if someone asked for certain text to be presented in red, it would be quite reasonable to ask for greater precision in the specification of redness or a reference sample of the particular shade desired.

In software engineering, such problems are mitigated (to a certain extent) by having defined colour schemes in which the numerical values of individual colour components (RGB, CMYK, HSL, etc.) are specified for each and every colour label. Such mitigations are only partially effective since the colour actually perceived by a user will also depend on the characteristics of the display device (its colour space, gamma, brightness, and contrast settings etc.) and ambient lighting conditions.

Attribute: Length – Value: 2m

Note that the value here involves a unit.

Attribute: Size – Value: Large

There is no reason for values to be objective: although formal criteria may be applied, context may suffice to give sufficient precision.

Attribute: Value – Value: High

Here there is an attribute that is called Value, meaning the worth of something. Note that the specific value of the attribute Value has been given as high but that the nature of worth has not been defined; it could be financial value, reputation value, or some other specific measure of goodness… or it could be an implicit reference to the contributory value of something to some higher level objective. One would hope that the context would make this clear.

It is probably not a good idea to have an attribute called Value.

Notes   [ + ]

1.UML Modeling Language (OMG UML), v2.5, §12.3.3.4 pdf here says, “A Stereotype is a limited kind of metaclass that cannot be used by itself, but must always be used in conjunction with one of the metaclasses it extends.” i.e. it is a named set of characteristics predefined for convenient reuse which can be added to some other set of characteristics to characterise something.
2.UML Modeling Language (OMG UML), v2.5, §12.3.3.4 pdf here.

Pin It on Pinterest