Most of the time the action plan needed in a troubleshooting methodology is based on experience and analysis of documentation created by previous network engineers or operators. The process of creating an action plan involves documenting every one of the previous steps in the troubleshooting process, often by taking notes and using a PDA or an audio recorder to capture all the meaningful information along the way.
An important thing to remember is that you should act on one event at a time. If several problems occur simultaneously, you should prioritize them based on the way they affect users and the impact on the network and even on the business. Depending on the situation, you may want to delegate other technicians to specific technology areas in order to cover all the affected zones at the same time.
Once the action to be taken has been identified, you should implement a single fix/solution at a time. Do not try to mix different solutions just to hurry things up. Most often this will lead to other problems. You should move on to the next fix only if the previous one does not work.
Another important rule states that backup should happen first and rollback second. You should have a backup of the data, system, and configuration files before implementing the fix, and then you should have some way to roll back before attempting the troubleshooting solution.
Other special cases are the ones in which the problem is intermittent or the solution cannot be implemented outside production hours. If this is the case, you should carefully schedule a change control window and follow a strict procedure to cover every possible solution. You should always have a backup plan in case the primary solution fails; this will allow you to speed up the troubleshooting process and make maximum use of the scheduled maintenance window.
Do not panic if things get out of control. Ask your colleagues for assistance when needed and stay calm so you can maintain control of the situation.