POLITECNICO DI MILANO
Facoltà di Ingegneria
Dipartimento di Elettronica e Informazione

A STUDY OF BUSINESS RULES CONCEPT FOR WEB APPLICATIONS
 

Basi di Dati PROJECT



Relatore: Prof. Stefano CERI

Correlatore: Prof. Piero FRATERNALI
 
 
 

David PERRAULT


Anno Accademico 1997-1998

ABSTRACT



Business rules are an important aspect of an organization as they express policies that are running the business of the organization. But till now very few ways have been found to efficiently use business rules in the context of Information System Technology. This project is an exploration of the formal specification and possible implementation of business rules used for a particular kind of applications: Web applications. Our researches are part of the World Wide Web Intelligent Information Infrastructure (W3I3) project and based on the results of a previous project called Autoweb project. We will introduce a definition and classification of the subset of business rules applied to Web applications and will demonstrate practically their interests thanks to the Autoweb tools.


 


Ringraziamenti




Desidero ringraziare i professori Stefano Ceri e Piero Fraternali per il loro tempo e per avermi dato l'opportunità di lavorare in un ambiente ricco e stimolante come il Laboratorio di Basi di Dati del Politecnico di Milano.

Un pensiero speciale agli amici del Laboratorio per avermi ricevuto quando non parlavo italiano ed in particolare Andrea Maurino, Stefano Savo, Mario Ferloni, Emanuele Crespi, Matteo Kormos ed Hans Olav Damskog per il suo entusiasmo.


 

Introduction

I. PROBLEM STATEMENT AND WORK METHOD

II. Presentation of Autoweb and W3I3 Projects

II.1 The Autoweb Project

II.1.1 Overview

II.1.2 HDM-lite: a Conceptual Model for Web Applications.

II.1.3 From Conceptual Specifications to Physical Application Pages

II.1.4 The Autoweb System Tools

II.1.5 A Practical Example: CorsoOnLine Application

II.1.6 Short Studies of the Actual System

II.1.6.1 User interfaces

II.1.6.2 Usability of generated Web sites

 II.2 The W3I3 Project II.2.1 Overview

II.2.2 Brief Introduction to New Technologies

 III. Concept of WEB Business Rules

III.1 General Business Rules Background Information

III.1.1 Definition of a Business Rule

III.1.2 The Specification of Business Rules

III.1.2.1 Structural assertion

III.1.2.2 Action assertion

III.1.2.3 Derivation assertion

III.1.3 Requirements of an Implementation of Business Rules

III.1.3.1 Isolation

III.1.3.2 Abstraction

III.1.3.3 Integration

III.1.3.4 Responsiveness to business changes

III.1.4 Implementation of Business Rules

 III.2 Web Business Rules Presentation III.2.1 Overview

III.2.2 The Four Orthogonal Dimensions

III.2.2.1 Scope dimension

III.2.2.2 Data dependence dimension

III.2.2.3 Action dimension

III.2.2.4 Duration dimension

III.2.3 Web Business Rule Definition

III.2.4 Proposed Classification for Web Business Rules

 IV. FORMAL SPECIFICATION AND PRACTICAL SIMULATION

IV.1 Introduction

IV.2 Triggers Concept

IV.2.1 Condition Component

IV.2.2 Event Component

IV.2.3 Action Component

IV.2.4 Short Comparison of Triggers in Relational Systems

 IV.3 Secured Version of the Autoweb system

IV.4 Meta Language Specifications

IV.5 Practical Examples

IV.5.1 Web Business Rule #1

IV.5.2 Web Business Rule #2

IV.5.3 Web Business Rule #3

IV.5.4 Web Business Rule #4

IV.5.5 Web Business Rule #5

IV.5.6 Web Business Rule #6

IV.5.7 Web Business Rule #7

 V. Customizable Web business rules

V.1 Template Description

V.1.1 Template #1

V.2 Template #2

V.3 Template #3

 V.2 Web Business Rules Generator

CONCLUSION AND FUTURE WORK

Bibliography

Appendix 1

Appendix 2

Appendix 3


 Introduction

The professors Piero Fraternali and Paolo Paolini have initiated the Autoweb Project [1] in 1996. It focuses on the methodologies for the development of applications for the World Wide Web based on the integration of design notations, techniques, and tools from the world of Information Systems and Hypermedia applications. Since the beginning of the project, a complete set of tools has been produced and many applications have been created for Italian companies.

Based of this first approach, the World Wide Web Intelligent Information Infrastructure (W3I3) project has been proposed to the EEC in December 1997 and accepted in May 1997, with a starting date set for September 1,1998. The responsible of this project is the professor Stefano Ceri [2] at Politecnico di Milano. Its goals are very similar to those of the Autoweb system. The idea is to improve the concepts applied by the Autoweb system and to introduce new technologies such as the language XML, the Cascading Style Sheets or new conceptual methodologies. The support of business rules is one of these improvements.

The concept of business rules is not new. Companies have already tried to integrate their business rules in their computerized applications however with few successful results. What we propose is a classification and a formal approach, which simplify the declaration of business rules inside a Web application. With the support of business rules, the Autoweb system will give to the author a complete control on his Web applications.

This document is structured as follows. In section 1, we present the Autoweb system and the first specifications of the W3I3 project. Then, we introduce the concept of business rules applied to Web applications. In the following section, we present practical examples and their implementation in a secured version of the Autoweb system. Finally, a set of customizable Web business rules to integrate in a new version of the Autoweb tools is given.