The claim is invalid since the ditch removal has no technical impact in the IDAS System, however changing the locations of the microwave devices to ensure system performance is under the responsibility of the contractor and part of the scope. In addition, both IDAS FSD and HCIS requirement does not limit the distance between two microwaves at exact 160 meters thus it mentioned there that there will be an option to adjust the detection plus/minus 150 meters or better.