Requirements Validation Through Scenario Generation and Comparison

When designing systems, we must solve many problems associated with the correct definition of system requirements, the right understanding, and proper implementation. Finding that design or implementation contains an error or is incomplete, and identifying where a change needs to be made, are different issues that require different approaches. Models and diagrams, often diagrams from the Unified Modeling Language (UML), are used to capture the system’s requirements and basic design. The basic ones include the domain model, use case diagram, activity diagram, and scenario models. Scenarios show the communication and cooperation of objects in solving the use case under specific conditions. If the system is implemented following the design, it is possible to generate scenarios at runtime (either actual implementations or using simulation models). Thus, we can have assumed scenarios of the investigated use case’s behavior and real scenarios reflecting the performed design. In many cases, it is not useful to have a detailed view of the entire communication between objects. However, it is enough to focus on specific parts, such as messages or states of objects. In this paper, we will focus on detecting discrepancies between expected and actual behavior and quickly identifying the problem’s location through scenarios. Keywords–Requirements modeling; simulation; scenarios.