"Once you make a can of soda, you cannot return it back to its basic components such as carbonated water, citric acid, potassium benzoate, aspartame, and other ingredients. You cannot put the juice back into the orange. A car or computer, on the other hand, can be disassembled and the parts, to a large extent, can be returned to stock."
"... if the formula calls for 1,000 pounds of cake flour, but one only has 500 pounds, one can still bake cakes, just not as many. Conversely, in discrete manufacturing, one missing part means waiting for it before the finished assembly unit can start rolling off the production line."