An Architectural Approach to Requirements Engineering for Infrastructure Projects

A brand-new high-speed railway project such as HS2, currently under development in the United Kingdom, presents a requirements engineering problem that is similar to domains where Systems Engineering (SE) is more traditionally applied, such as an aircraft, but with some differences in system structure that preclude a direct mapping of routine techniques. With over 300 separate elements of design in the Country South portion of the route, fitting into roughly 20 categories and inheriting requirements at multiple levels, including location-specific constraints, it was considered necessary to implement a model-based solution to provide an adequate level of technical assurance by managing the requirements and their links to the design elements. A database tool with diagramming capability was used to create a visual traceability structure between the client's original requirements and the refined requirements. A layered model of the system architecture was used to apply requirements to the correct sets of individual design elements. From this combined requirements and architecture model, spreadsheet checklists were generated for designers to perform verification. The resulting data were then re-imported to the database and processed into a detailed report for submission to the client. The solution developed automates assignment of requirements traceability in order to provide exactly the right set of requirements for each deliverable on the route, which may consist of multiple asset types in differing combinations and with local requirements as well as more generic requirements assigned by equivalence.