The number one way to keep the system going is to have an offsite backup. If the main site goes down for lack of internet or a power outage, then you have another site ready to go. Ideally you would want the other site somewhat far away, so any local issues won’t affect it. The backup site needs to be kept up to date. You never know when something will go wrong. Having the backup site with the current software, hardware, and data is a must.
All software needs to be fully patched and updated. They have been stories where a patch was out, but the company didn’t get around to updating everything and an avoidable attack happened. As a Chief information security officer, you would be making sure that the people that update the systems know about the patch and are working on it.
You need to watch out for slow acting attacks. Maybe the system will still be active during an attack until the attack hits a peak causing the system to crash. It is important to monitor network traffic to see if anything unusual is happening. Setting up Firewalls to block unused ports can help safeguard your system. If you want to be a bit tighter the Firewalls can also block all traffic that isn’t on select allowed ports. That will lower the entry points into your system.
You can have training sessions that teach the dangers of cybersecurity. A lot of people may not know that a simple email link to a “cat video” could be a bad link that will infect the computer. Having a list of dos and don’ts can greatly help the user error.