b. PileMode

1) Free combination: no restriction on loading; any combination is allowed.

2) Place the same cargoes next to each other: sometimes for easier on-site loading and sorting, the same cargo should be placed together when designing the plan. Use this together with cross depth.

3) Only cargoes with the same length and width are allowed to stack on top of each other: only cargo with the same length and width may stack, producing a layout that goes from high to low.