Browse Prior Art Database

Functional Modeling using Object Collaboration Diagram

IP.com Disclosure Number: IPCOM000113193D
Original Publication Date: 1994-Jul-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 6 page(s) / 171K

Publishing Venue

IBM

Related People

Bonnell, RD: AUTHOR [+2]

Abstract

To effectively comprehend, communicate, and validate a domain of discourse, three aspects of the domain must be modeled:

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 37% of the total text.

Functional Modeling using Object Collaboration Diagram

      To effectively comprehend, communicate, and validate a domain
of discourse, three aspects of the domain must be modeled:

1.  Structural:  Generally modeled with data modeling techniques such
    as entity-relationship diagram depicting the structural
    relationships between data types;

2.  Behavioral:  Generally modeled with Petri net or state chart to
    show the time-dependent behavior of objects;

3.  Functional:  Generally modeled with data flow diagram showing
    transformation of data by specific functions [1-5].

      Various object-oriented analysis methodologies have been
presented to represent aspects of a domain of analysis [6-10].  But
most of them have fallen short in providing a set of object-oriented
constructs to depict the functional aspects of a domain.  The term
function is used not as the algorithmic abstraction.  Rather,
function expresses the role and responsibility an object plays as it
collaborates with other objects in response to an event of
consequence.  A functional model in the object-oriented paradigm is
therefore concerned with making explicit the functions an object
brings to bear as it exchanges data with another object and then
transforms this data for the same object or for yet another object.

A functional model is an integral part of a domain specification, for
the following reasons:

1.  In the object-oriented paradigm, a system is viewed as a set of
    objects collaborating with each other through their respective
    roles and responsibilities.  A functional model depicts objects'
    responsibilities in terms of the types of data shared.

2.  The functional model provides a high-level framework in which the
    pertinent domain concepts are related by functions--"what has to
    be done".  This framework becomes a key input to identify objects
    and to understand their roles and responsibilities.

3.  The object model (also called the structural model) alone
    provides an incomplete (albeit necessary and important)
    specification of a domain because the object model only suggests
    the possible interactions through its aggregation and association
    relationships.  The object model does not reveal what data are
    involved in the interactions.  Contrarily, the functional model's
    purpose is to depict these interactions in terms of objects'
    roles and responsibilities and the type of data or object
    involved in the interaction.

      The object collaboration diagram discussed in this article is
used to represent the functional aspect of any domain of discourse.
Before the modeling constructs are described, the following domain
concepts to be modeled are first defined:

1.  External entity:  A source or destination, outside of the domain
    of discourse, for input or output information, respectively.

2.  Active object type:  An objec...