They kind of can - you can lower the duty cycle and batchify things. You can also outsource to them, and/or otherwise share them with other producers/production lines. I personally believe future manufacturing will be significantly more dynamic with respect to assembling/disassembling production line unit operations via electronic contract (re-)negotiation.

At http://8-food.com/ we are essentially placing miniature (fresh food preparation) factories in retail spaces, and so I've been reading a lot of industry literature recently. I've found very interesting crossovers with former work on a major Bitcoin exchange - eg. multi-asset/service/settlement path capable transaction markup and negotiation systems - http://ifex-project.org/ In the same way factories use JIT (just in time) concepts to optimize inventory and supply-chain logistics, we similarly optimize for delivery of ingredients and packaging, and thus reduce storage bulk overheads and achieve form-factor minimization. Operations research truly is operations generic, and quaintly fascinating coming from a programming background.