Suggested Business Rule
Structure
As discussed
in the introductions, rules should
be defined in the class model (ACM). This should
be done by adding an operation to the appropriate class, giving it
suitable name (of the rule) and providing a description of what it is
trying to do.
What is
documented within the rule in principle is not really that different to
what is typically described in an (say) XL list, however where it
is documented becomes important. Note that the translation of what is
traditionally though of as a business rule to these operations is not
necessarily on a 1-to-1 basis. It will certainly require additional
analysis activity thinking along classic O-O lines: what (class) has the
responsibility to undertake the behaviour suggested by the rule.
For example:
the trade object may be expected to “validate” itself, but to do so it
will need to collaborate with other objects, e.g. instrument.
It is not recommended that
a structured syntax (e.g. OCL, pseudocode) is used to describe these rules
still need to be validated as part of the business domain (however their
later specification can use these). Nonetheless the business rule
should document either in the description or as part of the operation
signature:
 | Business logic
concerning behaviour and any collaboration that is not self evident from
the ACM |
| Any parameters required
and what part they play in the business logic. |
| Range of possible
outcomes (these could be
simple (pass/fail) but could be more complex. However in all cases the
outcomes should be finite (e.g. in implementation would have a unique
code) and definable (the business logic that would result in the outcome
should be clearly defined) |
|
Optionally, for complex behaviour, separate Activity or State Diagrams
for some classes can be also provided |
The
following sections explore in more depth the way these rules are
identified and described in the model.
Ó
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,
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