answer:If “the world collapses” there will be bigger problems than restoring food processing and packaging on assembly lines. One of the bigger problems will be finding people willing to raise food crops and livestock in quantity and able to defend the crops and stock from predators (including human ones), then reap it / butcher it, store it and ship it – and to be able to do that as well as willing. Even if the grower is found and can do the job, and then even if the shipper will make the transportation of food to a processing plant that your nominal engineer can operate, and then even if another shipper can take the processed food to market, there still needs to be “a market”. That all implies regular commerce so that the farmer, shipper, engineer and marketer can resupply and operate whatever equipment they all need, safe roads to enable that commerce, some kind of currency or other portable means of exchange of value (barter is messy on large scale), and ways to conduct business over distance with trust. Large scale food processing is not going to be one of the first industries to re-emerge from a collapse of civilization.