Discrete EVent Systems Specification (DEVS) formalism supports specification of discrete event models in a hierarchical modular manner. This paper proposes a DEVS modeling language called DEVS Specification Language (DEVSpecL) based on which discrete event systems are modeled, simulated and analyzed within a DEVS-based framework for seamless systems design. Models specified in DEVSpecL can be translated in different forms of codes by code generators, which are executed with various tools for models verification, logical analysis, performance evaluation, and others. q 2005 Elsevier Ltd All rights reserved.