Reconstructing the Past: The Case of the Spadina Expressway

Alicia M. Grubb, Marsha Chechik, “Reconstructing the Past: The Case of the Spadina Expressway.” Requirements Engineering, 2020.

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Abstract: In order to build resilient systems that can be operational for a long time, it is important that analysts are able to model the evolution of the requirements of that system. The Evolving Intentions framework models how stakeholders’ goals change over time. In this work, our aim is to validate applicability and effectiveness of this technique on a substantial case. In the absence of ground truth about future evolutions, we used historical data and rational reconstruction to understand how a project evolved in the past. Seeking a well-documented project with varying stakeholder intentions over a substantial period of time, we selected requirements of the Toronto Spadina Expressway. In this paper, we report on the experience and the results of modeling this project over different time periods, which enabled us to assess the modeling and reasoning capabilities of the approach, its support for asking and answering `what if’ questions, and the maturity of the underlying tool support. We also demonstrate a novel process for creating time-based models through the construction and merging of scenarios.