A task is a building
block of a process that achieves some high level goal in the business. It
can thus be seen as being closely analogous to a enterprise level use case
(UC).
Tasks then break down
into a number of activities in a similar way that a UC breaks into a
number of steps.
An activity then is
an execution or implementation of a number of rules. Because different
rules can potentially apply in different circumstances (and in different
order) for the same activity, rule sets can be defined.
Figure showing relation of
business rules to the activities
Activities that
make up a task should be defined in an activity model
If a task is seen to
be a discrete UC, then the activities can be seen as steps within the UC.
This is not to say that each numbered step should have a separate named
activity, rather this should be logical groups of steps.
This can be shown in
an activity model, with any product specific differences in flow shown. A
single model can suffice or separate ones if the differences between
specifics and generic case is too great.
Figure showing relation of
Activity to Task
Sets of Rules that
make up an Activity should be defined in a sequence model
Each activity within
a UC should have sequence models that describe what rules apply, for given
scenarios in what sequence and how they collaborate. Since these rules are
operations from the ACM artefacts the participating classes form part of
this model.
Figure showing sequence
models and Rule Sets
Note that these
scenarios are effectively the rule sets. Since different rules can apply
say to Bonds to say the generic case, separate scenarios should be put for
each of these cases, each clearly showing what it applies to (e.g. “bond
specific”, “swap specific”, “generic” etc).
©
2002-2005 Codel Services Ltd
This paper has been prepared
by Codel Services Ltd to illustrate how structured business
modelling can help your organisation. Codel Services Ltd is an IT
Consultancy specialising in business modelling. If you would like further
information, please contact us at: Deryck Brailsford, Codel Services Ltd,
Dale Hill Cottage, Kirby-Le-Soken, Essex CO13 0EN,United Kingdom.
Telephone: +44 (0)1255 862354/Mobile: + 44 (0)7710 435227/e-mail: info@codel-services.com
