In this paper, structurally adaptive and dynamically reconfigurable sy
stems are presented as important ingredients in the design and develop
ment of robust large-scale signal processing systems for operation in
complex, nonstationary environments. The multigraph programming and ex
ecution environment (MPEE) simplifies the design and implementation of
such systems because of its graph-based computational model, support
for dynamic scheduling, multiprocessor programming capabilities, model
-based approach to system design, and graphic editors. Using MPEE is i
llustrated by a structurally adaptive system example that highlights b
oth the capabilities of the MPEE and the nature of structurally adapti
ve and dynamically reconfigurable systems. This example, a signal extr
action system, also shows how to deal with transients produced by abru
pt changes in filter characteristics of filters during run-time.