Accession Number:

ADA359957

Title:

A Framework for the Certification and Evaluation of Real-Time Safety-Critical Intelligent Systems

Descriptive Note:

Final rept Jul 95-Oct 97

Corporate Author:

ILLINOIS UNIV AT CHICAGO CIRCLE DEPT OFELECTRICAL ENGINEERING AND COMPUTER SCIENCE

Personal Author(s):

Report Date:

1999-01-01

Pagination or Media Count:

22.0

Abstract:

The concept of software architecture has recently emerged as a new way to improve our ability to effectively construct large scale software systems. However, there is no formal architecture specification language available to model and analyze temporal properties of complex real-time systems. In this paper, an object-oriented logic-based architecture specification language for real-time systems is discussed. Representation of the temporal properties and timing constraints, and their integration with the language to model real-time concurrent systems is given. Architecture based specification languages enable the construction of large system architectures and provide a means of testing and validation. In general, checking the timing constraints of real-time system is done by applying model checking to the constraint expressed as a formula in temporal logic. The complexity of such a formal method depends on the size of the representation of the system. It is possible that this size could increase exponentially when the system consists of several concurrently executing real-time processes. This means that the complexity of the algorithm will be exponential in the number of processes of the system and thus the size of the system becomes a limiting factor. Such a problem has been defined in the literature as the state explosion problem. This paper proposes a method of incremental verification of architectural specifications for real-time systems. The method has a lower complexity in a sense that it does not work on the whole state space, but only on a subset of it that is relevant to the property to be verified.

Subject Categories:

  • Computer Programming and Software
  • Computer Systems Management and Standards

Distribution Statement:

APPROVED FOR PUBLIC RELEASE