Transcript Diapositiva 1

OOPSLA 2006
6 th Workshop on Domain-Specific Modeling
October 22, 2006
Oregon Convention Center, Portland, Oregon
Conceptual design of web
application families:
the BWW approach
Roberto Paiano – [email protected]
Anna Lisa Guido – [email protected]
Andrea Pandurino – [email protected]
The scenario
When the application domain is very large and several
applications can be obtained from the design, it is
important to formalize in some way the domain
knowledge.
To manage this complexity in the design of specific
application many methodologies are born; especially in
the design of web application.
The scenario becomes more and more complex when
the designer has to model not a specific application
(that solves a specific problem) but a family of
applications about a knowledge domain.
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Domain
Layer
Conceptual
Layer
Application
Layer
The overall scenario
Application
Model
Application
Knowledge
Domain
Knowledge
Model
Methodology
Technology
Model
JAVA/ MS.NET
Conceptual Application
Model
P-IDM
W2000-UWA
User Experience Model
IDM
Requirement Elicitation
AWARE/ Goal oriented
approach
Conceptual Domain
Model
BWW/UML
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The conceptual model experience
Many well-known methodologies exist to model
and develop the specific application but there
isn’t a standard approach to model the whole
domain knowledge.
The main goal is to introduce an experience in
the conceptual model of a specific domain.
This experience has been performed into the industrial research project called “Genesis-D”
(Global Environmental Network System of Information for Sustainable Development)
sponsored by Edinform SpA.
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The environment domain
It is a very complex application domain
Great number of stakeholders
The necessity to acquire and to organize the
knowledge from different sources
Coherent data exchange between the different
stakeholders
Different objects are used with the same
semantic in different contexts
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The two approach
In detail, we evaluate the objectiveness and
usefulness (in order to design and to develop a web
information system) two different approaches:
The use of classic techniques within software engineering.
Due to the domain dimension and complexity, it is too hard
to use a fully-compliant UML approach, thus, the UML-like
approach adopts the main concepts of Object Oriented
customized for the specific purpose.
The use of the formal ontology. This approach uses the
classification of the concepts proposed by BWW in order to
represent the domain concepts and their relationships with
a well-known semantics.
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The UML-like approach
At the conceptual modeling abstraction level it
seems unsuitable to use a fully-compliant
Object Oriented approach.
According to the abstraction level and to the
necessity to manage all the information in a
few diagram (in order to not have a
fragmented design), in the conceptual model
we use only the class diagram.
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The UML-like approach
In the UML-like approach the modeling process is
made up through several iterations: each iteration
has the goal to refine the analysis and therefore to
describe the application domain in a more and more
precise way.
Because of the conceptual modeling abstraction level,
it is not possible to use “object” for which it is
necessary to identify the state and behavior of entire
domain reality.
In the diagram, we use the “Entity” that may
contain some attributes.
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The UML-like approach steps
Step
Description
Example
1. Analysis of
entities
Provide a
description of the
information
entities and the
relationships
among them
Alteration biological variety, climatic
change, consumption of soils, soil
degradation, pollution, wastes
radiation, noise, FIA class (Fact of
Environmental Interest) For FIA class
all the parameters are grouped in the
IIP class (Indicator, Index, Parameter)
2. Analysis of
entities attributes
Entities are
refined (through
the definition of
the attributes, of
their type and of
the methods)
For Features: Name, period of life,
Category, status
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The UML-like approach example
1..*
OSS
In the UML-like approach the designer
describes
0..*
FIA
the phenomena creating the FIA class (Fact of
1
Environmental
Features Interest) and *all the parameters are
Using
an
analogous
1..*
grouped in the IIP class (Indicator, Index,
procedure, other abstract Name
Category
classes are identified: Parameter) strictly related to the Metrics class.
Period of life
Objects
, Subjects and Category
1..*
1..* 0..*
Structures (OSS) to which Status
each FIA
makes reference.Description
*
Status measures
IIP
0..*
FIA, IIP and
Metrics are
Abstract Classes.
*
0..*
Metrics
OST
Name
0..*
Water Body
Feature
Type
SOI
1..*
1..*
Antropic Obj
Name
juridical
Type
*
1..*
The class OSS contains the Subjects (physical or
person that can be
or involved in facts and environmental phenomena), the Objects
or territorial structure inside which the characteristic processes of
the human social lifetime are based and are developed) and the Structures.
Range
interested
Algorithms
Description
(any object
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The use of BWW concepts
The BWW concepts classification are adapted
to our needs:
Adding the relationship of a thing with itself;
Adding property in order to characterize the
events.
In detail, using the OWL:
first we defined the meta-model of BWW concepts;
then using the meta-model, the environment
domain model (target of our research work) is
modeled.
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The BWW approach steps
Step
Description
Example
1. Analysis of
things
Highlight domain
thinks
Water Basin, Water Body,
Public Corporation
2. Analysis of
classes
Highlight domain
classes
The properties shared between
Water Basin and Water Body define a
class (Hydrographic object)
3. Mutual property Select mutual
property of each
class
4. Intrinsic
property
For Public Corporation:
Regulation, dimension, category,..
Select intrinsic
For Public Competence :
property of each
Name, function,..
thinks and classes
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The BWW approach steps
Step
Description
Example
BWW Property
5.
each mutual /
Characterization intrinsic property is
of property
tied up to both
human and natural
laws. This
characterization of
the properties
introduced by BWW,
has led us to reflect
them in the
environmental
domain.
The territorial competences
of the
BWW Law
Public Corporation are, for instance,
defined by decrees. The decrees
result, therefore, in a characterization
of the Intrinsic Property territorial
competences and, particularly they
are Human Law: this means that
territorial competencies are
constraints by the Human Law
decree. BWW attributes allow us to
take into consideration the correct
semantic of a concept (decree).
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The BWW approach steps
Step
Description
Example
6. Events
Define what it
happens: the events
are in partnership with
a thing or class and,
when they occur,
change a well defined
property of the Thing
or of the class to
which they are
associated.
An OSS creates a FIA that, in turn, is
created when the variation of an indicator
produces an alarm. The alarm is an
events.
Select different part of
the same Conceptual
model
BWW defines the systems as the joining
of things intending that the things
belonging to the system influence the
properties of each other
7. System
Using the BWW approach the FIA has
been modeled as an history of the value
of indicators; thus, the concept of FIA
has the correct semantics.
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Comparison between the two approaches
BWW approach advantages:
Objective: the concepts classification helps to represent the
application domain without focus on a particular point of
view.
the domain model is directly expressed using well defined
and categorized domain concept through real world concept
such as thing, classes, law and so on where the domain
concept is easy to map.
It supports directly Events and the concept of input and
output in relationship with the concept of thing: is coupled
with, generate output and so on (intrinsic in BWW) give the
right semantics.
It is easy to realize and easy to use for those who will deal
with the following phases of analysis and implementation.
It is technology independent.
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Comparison between the two approaches
The UML-like approach allows to describe a domain
using an incremental method.
Advantages:
the designer improves the analysis step by step
the output can be directly used through the UML standard
notation to create the final product
Disadvantages:
the output is an Object Oriented model that implements the
typical constructs of this paradigm.
the process is strongly dependent on the experience of the
designer who must analyze the application domain and
must be skilled at OO modeling
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Comparison between the two approaches
The main UML-like disadvantage is that the
semantic is flattened and the concept of entity
is used also to model very different concepts;
For instance, in the UML-like modeling, the FIA and
the indicator are both modeled as entity but the
FIA is a set of values (not previously defined) that
the indicator can assume at the time: a FIA is
registered when some value of an indicator
changes.
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Conclusions
The case study presented in this research work
is very complex, so we think that the
considerations made for this case study are
also valid for other case studies.
To check the BWW domain model, we also
studied the WA used by the Authority of basin
of PO river that is perfectly represented into
the conceptual model designed.
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Conclusions
The BWW approach allows the provision of the right
semantics and therefore it expresses all the domain
details directly using the domain concepts. The model
is objective thanks to the classification of the
concepts provided by BWW and it is not tied to a
specific implementation technology.
The UML-like approach appears particularly effective
because, being a lot closer to an implementation
technology, allows us to directly reach the realization
of a family of applications in a particular application
domain.
The objectivity and the simplicity of the BWW
approach encourages the use of this approach for the
conceptual modeling of application domains of great
dimensions.
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Future trend
In order to keep under control the typical aspects of
web applications and therefore to manage the user
experience, we are designing two web application
starting from the conceptual model of the
environment domain.
Our efforts are focused on the definition of guidelines
to obtain an IDM (Interactive Dialog Model) design
starting from the domain modeling.
As future work we plain to design and implement an
editor in order to help the designer to apply the
guidelines that we are defining.
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