2 concepts here and Larrys covers one very well.
The other is a featured industry with the normal large industry sprawl which many newer layout operators are going to.If you want many small industries larry's methodology will work best.
If you want to use this as a featured industry(and a large cannery makes a very good one due to multiple car types and the fact that railshipments to Distribution points are still being utilized to this day)
Seperate Shipping and Recieving area's each with multiple tracks can be used.
Additional trackage for the plant if it has its own power plant.( Era can make a huge differance here) An Icing platform and Ice track for cars that are loaded but not ready to be processed,Are we canning fruits and vegetables?? How about meats??If we have meats this will be a seperate area of the plantwith livestock pens,slaughterhuse etc(do you see how plant sprawl takes place here?)
We have to can so we need cans.Are we buying these or are we manufacturing them ourselves?? So we are buying rolls of Tin and we have yet another building for the machinery to make the differant cans.We can at this point certainly justify a dedicated plant switcher if we would like creating 1 job for operating.A Plant of this magnitude is likely going to have pickups and setouts as much as twice a day by the class 1 RR considering the nature of the product.(Orders of several boxcars going to IGA and another pickup in the Evening to the Piggly Wiggly or A&P distribution centers as an example)Also, if you are more modern and include for example a processing area for fresh produce(example Dole plant making bagged salads) Or meat products (prepackaged bacons,lunchmeats etc)
Hormel makes canned Chili's,Beef stews. They also have bacon,sausage,Canned hams,lunchmeats etc.
Campbells makes canned soups.Do they process thier own noodles?? Chicken?? Beef??
This one industry may employ 1/2 the town it is located in.An entire branchline may be in place specifically for this one industry.
This is the other scenario.neither is right or wrong,they are just differant and require differant approaches.This industry could become a layout unto itself if one so desired.Few would desire this but some have done this type thing(particularly with stell mill and paper mill type operations)
Study some differant operations.Find out how they do things and why.See if a sprawling industry is something that appeals to your sense of railroading.See if 1 really large industry will complement your vision.There is always of course a happy medium between the 2 also.The choice is yours,its your world
So, there you have it,options!!! And dont we all like to have options
