A business activity (BA) is a (repeatable) pattern of operations undertaken by an organizational unit to reach a certain business goal. An activity is a compound structure and allows decomposition to a certain level of granularity (see business process). It is a main building block for behavioural description of the business domain.

Every business activity can be seen from two different perspectives. The how perspective, describes the pattern of operations composition for achievement of a certain business goal. The what perspective deals with the impact of the activity execution on the business domain and relations to other activities. Such a separation of concerns helps us to come up with two different representations of business dynamics, namely with business processes and business capabilities respectively.

Business activity is introduced in literature as a technical term representing a part of a process that is executed for achievement of a business goal. Therefore the term is strongly related to the business process term. Especially the business definition points out the business process as a primary abstraction. In contrast to that, PDD uses the term business activity, to represent both, the what and the how aspect and does not judge on the rank of these two terms.

A business activity is represented in PDD Model using a Activity entity. It is an element of the PDD Core model. From the modeling point of view the assumption is made, that the activity is an abstraction of a primary behavioral concept from the business domain, which is independent from the perspective.

The business activity may also be refered to as a business function, business action or business process step.

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