Recent research in the system level design field has produced a number of techniques for structuring the understanding of systems. Many of these techniques produce design structures that are easily expressible in Ada language. Ada language has a structure which allows the design of systems to be expressed independently of its implementation and thus can be a good system design language to use with these techniques. This paper describes how to use Ada as a system description language like SystemC, which will use Ada compilers (such as Gnat) to evaluate the written program as a system; we have named it, SystemAda. This paper reviews Ada programming language requirements for modeling system behavior and structures at Transaction Level Modeling (TLM). This paper considers possible approaches for extending Ada to meet these requirements.