![](bg5.png)
A general Pre-RS traceability framework is illustrated in Fig. 3. Classes at the
conceptual level, actors and use cases (as software functional requirements),
functional requirements and system goals set by users (users’ desires) are traced to
TFM functional features, traceability between which at different levels of abstraction
is also provided. Hence, it is possible to determine why a class or a requirement is
included in the software solution, and how it is linked with other structural or
behavioral elements by using the formal ground – formally related topological models
of business and information system functionality.
4 Pre-RS Traceability in Case of the Perfective Change Request
For illustration of advantages of the introduced formalism, let’s take a little bit
simplified example that describes an information system of the library “Library IS”.
4.1 The CIM – Business Model
The TFM of BS (The Library)
is presented in Fig. 4a. Description of functional
features (FFs) is given in the form “identifier: feature_description, precondition,
responsible_entity (where, “Lib” denotes “librarian”, and “R” denotes “reader”)” and
they are as follows: 1: Arriving [of] a person, {}, person; 2: Creating a reader
account, {unregistered person}, Lib; 3: Creating a reader card, {}, Lib; 4: Giving out
the card to a reader, {}, Lib; 5: Indentifying a reader, {}, Lib; 6: Completing the
request for a book, {}, R; 7: Registering the request for a book, {}, Lib; 8: Taking out
the book copy from a book fund, {a book copy is available}, Lib; 9: Checking out the
book copy for a reader, {}, Lib; 10: Giving out the book copy to a reader, {}, Lib; 11:
Getting a book copy, {}, R; 12: Returning a book copy, {}, R; 13: Taking back the
book copy from a reader, {}, Lib; 14: Checking the term_of_loan of a book copy, {},
Lib; 15: Evaluating the condition of a book copy, {}, Lib; 16: Imposing a fine, {the
term_of_loan is exceeded or the condition is damaged}, Lib; 17: Returning the book
copy to a book fund, {}, Lib; 18: Paying a fine, {imposed fine}, R; 19: Closing a fine,
{paid fine}, Lib; 20: Completing a statement_of_destruction, {hardly damaged book
copy}, Lib; 21: Sending the book copy to a destructor, {}, Lib; 22: Destructing a
book copy, {}, Destructor.
User Requirements (Functional)
are dedicated to receiving an IS that supports
servicing readers. They are the following - FR1: The system shall register a new
reader; FR2: The system shall check out a book copy; FR3: The system shall handle
return of a book copy; FR4: The system shall account reader’s fines.
Tracing: The requirements map onto FFs of the TFM of BS as follows (Fig. 4b): FR1
to {2, 3, 4}, FR2 to {5, 7, 8, 9}, FR3 to {5, 13, 14, 15, 17}, and FR4 to {16, 19}.
The TFM of IS
is illustrated in Fig. 5a. After formal identification of the IS, a
subsystem of the BS, it excludes only two functional features - 21 and 22.
System Goals to is Set by Users
are needed for TFM decomposition into use cases.
The goals are stated as follows: SG1 “Register a reader”, SG2 “Check out a book”,
40