just think of the points you could simulate and simulate them. You could simulate that there's a fire , the alarm will set off, people will go out using the emergency doors , you put that into protocol and you're done. If you cannot simulate equipment breakdown , check out your area or any similar manufacturers and ask them if they could help you (if relevant) to produce XYZ parts (assume your 2-3 days volume , also assuming in 2-3 days you can fix your equipment) and see what will be the outcome. Contact , ask, put this as a evidence. Then you demonstrate that in your contingency plan and it is something real and you will know how to react. The same goes for supply chain issues. If you have problems with suppliers (or supplier goes out of business and you will know that in advance) , contact similar manufacturers in the area and ask them if they work with similar products that your supplier was shipping to you. If yes , you can study this product and if you're happy with the results and the characteristics you could use this until you stabilize your supply chain. Of course product changes should be communicated with customer. It's a good to have plan and remember that no plan is perfect.
