A mistake in the rule set can render a firewall insecure. Therefore, testing and validating the rules is the most important factor in ensuring a successful deployment. A regular review of log files would not start until the deployment has been completed. Training a local administrator may not be necessary if the firewalls are managed from a central location. Having multiple administrators is a good idea, but not the most important. <== All the statements are critical to a firewall deployment. I would argue that split duties, change management and log review are more critical than testing and validating the rules, since that can be tweaked post-deployment.