Using business use cases to model the basis of business activity diagrams

[fatass]

Often we struggle to define properly our business workflows, both from
the perspective of the level of detail at which it should be modelled
and from a completeness point of view. Another problem that faces us,
as modellers, is the reuse of activities in order to create an
environment that is lean, optimized and as standardized as we possibly
can get it.

When we already have a consistent business use case model, it may be
used to create a first cut activity flow model. A business use case
typically represents a business function. Using the definition of an
elementary business function, a business use case should be a self
contained unit of work, executed by a single primary actor, from start
to finish, with no intervening time delays. Higher level functionality
should be represented using packages and package diagrams.

With a business use case model already developed we can make the
reasonable assumption that a business activity = the execution of a
business use case. As such we can derive our business activities from
our business use cases and just arrange those derived activities in
the preferred workflows.

This can then serve as the first cut business workflows.

We may still at this time detect that activities exist for which no
corresponding business use cases exist. This is normally a good
indication that the use case model is incomplete and that additional
business use cases need to be added in the appropriate part of the
business use case model.

Mapping our complete business use case model against the sum total of
the activities present in the workflows may also show business use
cases that are not being executed in the processes. This may indicate
either redundant business use cases, or incomplete workflows.

Higher level workflows may then be derived from aggregating complete,
modular flows into higher level activities, all the way up to the
enterprise value chain.

Using both use case views and activity views in this way ensures a
consistent and complete model that is accurate in every respect.

Happy modelling!