dt = Open( "$SAMPLE_DATA/Cities.jmp" );
dt << Distribution(
	Column( :OZONE ),
	Fit Distribution(
		Weibull(
			Spec Limits( LSL( 0.075 ), Target( 0.15 ), USL( 0.25 ) )
		)
	)
);
To set specification limits for K Sigma, use the Set Spec Limits for KSigma message. By default, the argument is two-sided. To make it one-sided, specify sided=1.
dt = Open( "$SAMPLE_DATA/Cities.jmp" );
obj = Distribution( Column( :CO ) );
obj << Fit Distribution(
	LogNormal( Set Spec Limits for KSigma( 3 ) )
);