Preliminary Requirements Checking Tool

Requirements play an important role in software systems developments. The impact of errors in requirements is costly, especially for safety and critical systems. Two kinds of properties are necessary in a formal requirements speci cation, applicationindependent properties and application properties. Application-independent properties are simple properties derived from the underlying formal requirements model and speci cation notation. Although detecting the failure to satisfy the application-independent properties is usually simple, the large size of requirements documents means that reviewers must spend considerable time and e ort checking them. Computer-supported preliminary checking tools are necessary for industrial application of formal requirements methods and improving the quality of requirements documents. In this thesis, a Preliminary Requirements Checking Tool (PRCT) is developed for this purpose. It checks the application-independent properties for SCR style requirements. The properties checked by PRCT are derived from the Four Variable Requirements Model [29] and Generalized Tabular Notation [27, 1]. The development of PRCT is based on the previous work on the Table Tool System (TTS) [31]. This tool will help to automatically check for errors like wrong syntax, unde ned variables and circular de nitions in requirements speci cation and will serve as a preprocessor for more advanced tools that will check the critical application properties of requirements. ii Acknowledgements I would like to express my sincere thanks and deep appreciation to my supervisor, Dr. David L. Parnas, for his guidance, insight, and enthusiasm throughout my thesis work. I have learned a lot from him in both academic and non-academic areas. Without his consistent encouragement and support, it would have been impossible for me to nish this work. I am grateful to Dr. Ryszard Janicki and Dr. Ridha Khedri, for reviewing my thesis, and for their valuable suggestions and comments. I would like to thank all the members of the Software Engineering Research Group, especially Jianwei Zhou and Min Jing, for their helpful discussions. Special thanks to my wife, Yun, and my family, for their love, encouragement and support. Finally, I would like to acknowledge the nancial support received from Natural Science and Engineering Research Council(NSERC) and Bell Canada. iii