Case Study of Feature-Oriented Requirements Modelling, Applied to an Online Trading System
The Feature-Oriented Requirements Modelling (FORM) combines the requirement engineering style structuring of requirements documents with the feature-orientation of the Feature Oriented Software Development, resulting in a feature-oriented model of the functional requirements of a system-under-development (SUD). A feature is a distinguishable unit of added value to the SUD. The objectives of FORM are to model features as independent modules, to allow the addition of new features with minimal changes to the existing features, and to enable automatic generation and checking of properties like correctness, consistency, and non-determinism. FORM structures requirements into three models: a domain model, a collection of behavioural models, and a collection of functional models. A feature is modelled by a distinct behavioural model. This dissertation evaluates FORM by applying it to a new application that can be thought of in terms of features, namely an online trading system (OTS) that receives requests from customers about buying or selling securities on a stock market. The OTS offers variability in terms of the types of orders that customers can request, (e.g. market order, limit order and stop order). The case study revealed six deficiencies of the FORM notation, three of which were easily overcome. The dissertation presents the results of the case study, resolutions to three of the six deficiencies, and an outline of an approach to resolve the other three deficiencies.