Conceptual design of web application families: the BWW approach

OOPSLA 20066 th Workshop on Domain-Specific ModelingOctober 22, 2006Oregon Convention Center, Portland, Oregon Conceptual design of web application families: the BWW approach Roberto Paiano – roberto.paiano@unile.it Anna Lisa Guido – annalisa.guido@unile.it Andrea Pandurino – andrea.pandurino@unile.it

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. Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

Model Methodology Application Model JAVA/ MS.NET Technology Model P-IDMW2000-UWA Conceptual Application Model Application Knowledge IDM User Experience Model AWARE/ Goal oriented approach Requirement Elicitation Application Layer Conceptual Layer Domain Layer BWW/UML Domain Knowledge Conceptual Domain Model The overall scenario Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

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 conceptualmodel 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. Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

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 Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

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. Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

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. Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

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. Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

The UML-like approach steps Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

The UML-like approach example In the UML-like approach the designer describes the phenomena creating the FIA class (Fact of Environmental Interest) and all the parameters are grouped in the IIP class (Indicator, Index, Parameter) strictly related to the Metrics class. Using an analogous procedure, other abstract classes are identified: Objects, Subjects and Structures (OSS) to which each FIA makes reference. • FIA, IIP and Metrics are Abstract Classes. The classOSS contains the Subjects (physical or juridical person that can be interested or involved in facts and environmental phenomena), the Objects (any object or territorial structure inside which the characteristic processes of the human social lifetime are based and are developed) and the Structures. Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

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. Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

The BWW approach steps Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

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. Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

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 Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

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. Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

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. Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

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. Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

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. Workshop on Domain-Specific Modeling October 2006 - Portland, Oregon

Conceptual design of web application families: the BWW approach