Thank you so much Pratiksha for your response. I guess it is a bit late that I am joining most of the deployment is gone. I still have that question which says. 

1. If I put it as Ignore = true when transforming for the following table 'cmdb_ci_lb_bigip'  cmdbutils API , it just ignores the record creation and gives me an matching attributes error but we have the attributes defined at the higher table class which is hardware. 

2. In order to counter it. there is a script defined with this it is working as expected, again the classification is based on category at the target table, but still want to use cmdbutils. I am bit confused why running a new load is ignoring the data...whereas when I set it to false...it is updating the information..there is an IRE defined, at the hardware level for correlation id & Serial number.

(function runTransformScript(source, map, log, target , isUpdate) {

	// Add your code here

	var existingRecord = new GlideRecord('cmdb_ci_lb_bigip');
    existingRecord.addQuery('u_id', source.u_id);

    existingRecord.query();

    if (existingRecord.next()) {

        log.info('Duplicate record found. Updating existing record with correlation_ID: ' + source.u_id);

    } else {
        target.correlation_id = source.u_id;
        target.insert();
        log.info('New record inserted with correlationId: ' + source.u_id);
    }
})(source, target, map, log, action === 'update');