Supporting systems engineering with methods and tools: a case study

Many projects have applied the Hatley-Pirbhai real-time structured analysis method to the definition and analysis of system/software requirements. Application of the method results in the generation of a functional requirements model, which includes data/control flow diagrams, plus process and control specifications. Although infrequently applied, the method also defines an architecture model, which specifies the physical components and the physical interconnect channels for the system. After first providing a brief overview of the architecture and requirements models, the authors discuss how the Hatley-Pirbhai methodology is being used by system engineers on a real-time embedded avionics program. They also discuss the set of automated tools used to support the methods, and how both methods and tools were tailored and enhanced. Lastly, they describe operational experience and some difficult lessons learned