A restricted natural language based use case modeling methodology for real-time systems

Abstract

Time-related properties are a critical type of extra-functional requirements for designing real-time systems. Modeling and validating time-related properties at the requirements specification and analysis phases is important for the successful development of real-time systems in terms of cost, quality and productivity. In the literature and practice, timing analyses (e.g., Worst Case Execution Time) are often performed to ensure that the design of a real-time system fully conforms to its time-related constraints. However, such analyses are mostly performed at the design and implementation stages, but not at the requirements level. This paper presents a restricted, natural language based, use case modeling methodology (named as RUCM4RT) to specify functional requirements of real-time systems as use case models, along with associated time-related constraints. RUCM4RT was proposed based on the UML profile for Modeling and Analysis of Real-Time and Embedded Systems (MARTE). In addition, in this paper, we also propose a metamodel-based formalization mechanism named as UCMeta4RT to automatically formalize use case models. We have conducted two real-world case studies to evaluate our solution and 40 use cases were modeled, among which 27 real-time use cases, 118 time-related constraints and 47 other extra-functional (also commonly called non-functional) constraints were specified. Results show that RUCM4RT was able to handle all the real-time related elements (e.g., time-related constraints) of the use case models.