Static timing and/or noise analysis are performed on a netlist of an
integrated circuit, to estimate behavior of the netlist and to identify
at least one violation by said behavior of a corresponding requirement
thereon, such as setup time, hold time or bump height in a quiescent net.
Thereafter, effect of engineering change order (ECO) to correct the
violation are automatically analyzed, based on the layout, the
parasitics, the timing and/or noise behavior, and the violation, followed
by generation of a constraint on the behavior (called "ECO" constraint),
such as a timing constraint and/or a noise constraint. Next, the ECO
constraint is automatically used, e.g. in a place and route tool, to
select an ECO repair technique, from several ECO repair techniques that
can overcome the violation. The selected ECO repair technique is
automatically applied to the layout, to generate a modified layout which
does not have the violation.