If the purpose of the business modeling effort is to re-engineer the target organization, consider maintaining two
variants of the Business Use-Case Model: one that shows the business actors and business use cases of the current
organization (sometimes called "as-is"), and one that shows the target organization with new business actors and
business use cases ("to-be").
If you are considering a significant redesign of the way the target organization works (business re-engineering), this
separation is needed otherwise the redesign will be developed without knowing what the proposed changes really
are at the end, and you will not be able to estimate the effects or costs of those changes. It is like an architect who
is asked to draw up plans for changing a townhouse into three flats, without having an as-is blueprint from which to
work.
The cost of maintaining two Business Use-Case Models is not insignificant, and carefully consider how much effort you
put into a current model. Typically, you would not do more than identify and briefly describe the business use cases*
and business actors. You would also briefly outline the business use cases you determine are key to the effort,
possibly illustrating this with a simple activity diagram. The level of detail you choose aims at providing a shared
understanding of the target organization.
You would not need this separation in the following situations:
-
there is no "new" organization (the goal is to document an existing organization)
-
there is no existing organization* (business creation)
Business actors in the use-case model are used by:
-
business analysts, to define the boundaries of the organization and describe the interactions between actors
and business use cases
-
user-interface designers, as input to capturing characteristics on human actors in the a system
-
system analysts, as input to finding system actors
*Note: when modeling an existing organization to create an as-is model, you need to do little more than create the
brief descriptions of business use cases, business actors and key business events and associate these with the existing
business goals because you can move more directly to capturing actual current business processes that realize these
business use cases. The current business use cases serve as anchors to explain the purpose of the current business
processes. When the purpose is business creation, the new business use cases are specifications for
achievement of the business goals, for a business that does not yet exist. Consequently, they will need much more
detail.
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