Ravi Ramdoyal

Reverse engineering user interfaces for interactive database conceptual analysis

The first step of most database design methodologies consists in eliciting part of the user requirements from various sources such as user interviews and corporate documents. These requirements formalize into a conceptual schema of the application domain, that has proved to be difficult to validate, especially since the visual representation of the ER model has shown understandability limitations from the end-users standpoint. In contrast, we claim that prototypical user interfaces can be used as a two-way channel to efficiently express, capture and validate data requirements. Considering these interfaces as a possibly populated physical view on the database to be developed, reverse engineering techniques can be applied to derive their underlying conceptual schema. We present an interactive tool-supported approach to derive data requirements from user interfaces. This approach, based on an intensive user involvement, addresses a significant subset of data requirements, especially when combined with other requirement elicitation techniques.

Interactively eliciting database constraints and dependencies

When designing the conceptual schema of a future information system, it is crucial to define a set of constraints that will guarantee the consistency of the subsequent database once it is implemented and operational. Eliciting and expressing such constraints and dependencies is far from trivial, especially when end-users are involved and when there is no directly usable data to play with. In this paper, we present an interactive process aimed to elicit hidden constraints such as value domains, functional dependencies, attribute and role optionality and existence constraints. Inspired by the principles of Armstrong relations, it attempts to acquire minimal data samples in order to validate declared constraints, to elicit hidden constraints and to reject irrelevant constraints in conceptual schemas. This process is part of the RAINBOW approach, destined to develop the data model of an information system based, among others, on the reverse engineering of user-drawn form-based interfaces.

From pattern-based user interfaces to conceptual schemas and back

Since the necessity to associate end-users of the future system with its specification and development steps has proven indisputable, it is crucial to define accessible means to express and communicate conceptual requirements between end-users and analysts in the context of Information Systems engineering. For this purpose, we present a simple form-based interface model offering an understandable and expressive graphical counterpart to a rich subset of the Generic Entity-Relationship model (GER). We describe how the elements of the proposed interface model can be translated into GER schema constructs, bearing the semantic characterisation of inter-concept relationships. The exposed principles support the automated translation of user-drawn form-based interfaces into a conceptual schema. The same principles can also serve as a basis to support the inverse translation process that aims at deriving a set of form-based interfaces from a conceptual schema.