Planning Modes
LOP offers three planning modes that trade off computation time against solution quality. You choose the mode each time you run the optimizer by clicking one of the three buttons in the editor toolbar. The right choice depends on how complex your shipment is, how much time you have, and how much every percentage point of utilization matters.
Quick Plan
Typical time: 1–2 seconds
Quick Plan runs the constructive heuristic only. The optimizer sorts items from largest to smallest by volume, then places each item into the tightest available space that satisfies all hard constraints, using a layer-based skyline algorithm with guillotine space splitting.
The result is a fully valid plan — no overlapping items, no weight limit violations, all hard constraints respected — produced almost instantly.
Best for:
- Checking whether a shipment will physically fit in a container at all
- Getting a quick estimate of utilization before committing to a full optimization run
- Simple loads with few items or items that are all similar in size
- Exploratory planning where you are testing several container type options in rapid succession
Quick Plan always produces a valid, executable loading arrangement. It is not a rough estimate or a placeholder — it is a real plan. For straightforward shipments, Quick Plan results are often good enough to use directly.
Smart Plan
Typical time: 8–12 seconds
Smart Plan runs the full two-stage pipeline: constructive placement followed by local search optimization. After the initial arrangement is built, LOP's local search engine makes thousands of small improvement moves — swapping item positions, trying different rotations, reinserting items into tighter gaps — accepting each change only if it improves the composite score.
This typically increases utilization by 5–15 percentage points compared to Quick Plan for mixed cargo loads, and often significantly improves weight balance and stability as well.
Best for:
- The majority of everyday freight planning tasks
- Shipments with a mix of item sizes where tight packing matters
- When weight balance and stability scores are important alongside utilization
- Production use — the quality-to-time ratio is optimized for real workflow use
Smart Plan is the recommended starting point for almost all shipments. If the result meets your requirements, there is no need to run Max Fill. Reserve Max Fill for situations where maximizing fill rate has a direct financial impact.
Max Fill
Typical time: 30–60 seconds
Max Fill runs the complete three-stage pipeline: constructive placement, local search, and a full metaheuristic search using Simulated Annealing. The metaheuristic phase explores a much larger space of possible arrangements than local search alone, including solutions that are temporarily worse in order to escape local optima and find a globally better arrangement.
For complex shipments with many items of varied sizes, Max Fill can find arrangements that are noticeably better than Smart Plan — particularly for plans that were close to full but left a few unplaced items that Max Fill manages to fit.
Best for:
- High-value shipments where maximizing fill rate has direct cost implications
- Complex loads with 100+ items of varied sizes and constraints
- Situations where Smart Plan leaves several items unplaced and you need to try harder
- Final planning runs before issuing a packing list to the warehouse
Max Fill is not always dramatically better than Smart Plan for simple or moderately complex loads. If your shipment has fewer than 30 items or items are all similar in size, Smart Plan will typically produce an equivalent result in a fraction of the time.
Progressive Results
All three modes update the 3D viewport in real time as the optimizer works. You always see the best arrangement found so far — you do not have to wait for the run to complete before you can evaluate the result.
For Max Fill runs, this is particularly useful: if the score looks excellent after 20 seconds, you can stop the optimizer early and use the current result. There is no penalty for stopping before the full time budget is used.
Comparing Modes at a Glance
| Quick Plan | Smart Plan | Max Fill | |
|---|---|---|---|
| Stages | Constructive | Constructive + Local Search | Constructive + Local Search + SA |
| Time | 1–2 seconds | 8–12 seconds | Up to 60 seconds |
| Utilization | Good | Better | Best |
| Score improvement over Quick | Baseline | +5–15% typical | +8–20% typical |
| Best use | Quick checks | Everyday planning | Critical shipments |
Re-Running the Optimizer
You can run the optimizer multiple times on the same plan. Each run starts fresh from the current item and container configuration. If you have made manual edits since the last solve, running the optimizer again will re-optimize from scratch using those changes as input.
Running the optimizer does not overwrite your manual edits to item properties (dimensions, constraints, quantities). It only replaces the placement positions. If you want to preserve a particular arrangement as a reference point before re-optimizing, use the Templates feature to save the current state.
Next Steps
- Understanding Scores — what the five quality scores measure and how to improve them
- Manual Editing — adjust individual placements after optimization
- Constraints & Rules — what hard and soft constraints the optimizer works with