The best plan is to recognize the potential of crisis. From there you need to have people who are solid leaders and are not panic stricken but can be problem solvers in conditions that may affect the key stakeholders and operations. A good crisis plan consist of what if questions. Brainstorming the what ifs and then creating organizationally accountability and responsibility for the challenges at hand. Clear communication that is two way between those that need to know should be regular and consistent. You may not come up with all the what ifs but with the mind set you have created the employees with accountability will step up to solve the problem.