TPBO

[FCIN]

Another thing I like to do is to have my crew arrive as a light engine move and only need to pick up 1, 2 or 3 cars, some days they may arrived with 1-3 cars.
other days the crew may have heavy work to do and still won't switch all the industries.

Ah yes, that's where the operational variety comes in to play!

Just because your layout has 5 industries doesn't mean that you would switch each one of them every operating session. Or if you have an interchange with another road and your interchange holds 5 cars that doesn't mean that every time you operate, you'd get 5 cars in and have 5 cars out. Of course you can sure do it that way, but doesn't work like that out there in railroad land.

When I worked for the F&C and the distilleries were in production (making the hooch), we might have 40 cars delivered to us by the L&N on Mondays because of the weekend build up, but the rest of the week maybe half or a quarter that many per day. When the distilleries weren't in production and only shipping out - we might run light to one of them or just take a couple of empties for loading and come back light or with only a handful of cars.

Some of your customers may be traffic heavy and require switching on a daily basis - even several times a day - but others might may only ship or receive cars once or twice a week - maybe only once or twice a month. Other customers are seasonal and may only ship/receive certain times of the year. Rural grain elevators or produce shippers being a examples of that.