Synthesis of reliability models from behavioral-performance models

This paper presents a modeling methodology in which a design-engineer can specify a design using a single model which is capable of encapsulating both the performance and dependability characteristics of a system. The model used by the designer is a simulation-based model in which the behavior of the system under consideration is described using a predefined set of primitive modeling constructs. The behavior and characteristics of each primitive construct are defined by a colored Petri net (CPN) which provides an unambiguous mathematical specification of the construct. Further, each primitive construct has associated with it a VHSIC Hardware Description Language (VHDL) description which has a one-to-one correspondence with the CPN definition of the construct. The primitive constructs presented here provide a modular approach to system level modeling using CPNs. The key feature of the methodology is that a single model is used to study performance, reliability, and behavior. This methodology eliminates the problem of inconsistency between the different models used to perform high-level analysis and trade-offs. Using such an approach, the same model may be used to study the behavior of a system as well as evaluate its performance and reliability characteristics