By Xi Du-02/16/2016

When it comes to customer service in transportation, the main target is to deliver goods to customers on time via the most cost efficient carrier. SAP Transportation Management offers best in class capabilities for route planning and carrier assignment based on complex constraints, legal reasons, customer preferences and carrier capabilities. However, no matter how sophisticated the transportation plan is, there is still the possibility that warehouse workers cannot completely load goods on the truck based on product availability, packaging changes or stacking dependencies, e.g. decreasing capacity by increased numbers of stops.  SAP TM addresses this detailed need with the load planning optimization engine.


What is load planning and what can it do?

Load planning provides the solution for how to find an appropriate location for each package/pallet on the truck under different physical constraints, e.g., dimensions, stacking factors, loading sequence, maximum weight on each axle, etc. SAP TM offers this feature as an out of the box capability, which is presented seamlessly in an interactive 3D visualization control, based on the SAP NetWeaver Visual Business component. The logic behind the optimizer is to achieve an optimal solution according to your business rules, allowing to certainly define rules and prioritizes (soft constraints) to control what your key loading objectives are, by considering all hard constraints defined by either the resource, product properties or simply business rules and customer preferences you have to consider. For example, failing loading any package/pallet onto the truck may cause very high penalty costs, which would be honored by the planning engine, but might challenge other objectives at the same time. You can also determine other objectives in the load planning rule, e.g., load all packages in each row straight, maximum height difference of stacks within a row. For the load planning rules, you can assign priorities, activate it or deactivate it, and also adjust certain attributes. By assigning priorities, the weighted (penalty) cost for violating the higher priority rule would be higher respectively.


Some of the constraints considered by the load planning optimizer are as discussed below:



Even for the same capacity (weight/volume) trucks, they may possible have different dimensions. So except volume, length, width and height of the product/packages and vehicle have to be matched. Once you have determined the dimension for each item and the vehicle, the proposed result must honor each of them individually. It is important to understand, that with SAP TM 9.3 SAP is also offering now complex packaging proposals even for individual orders, order or delivery items even at the individual consignment level (freight unit), even before the load planner will be involved, which will provide even more complex input for loading and shipping goods.


Stacking factors

Are important factors especially for the industry that has various product diversities, such as furniture, tubes etc. For example heavy packages/pallets shouldn’t be stacked on light packages/pallets so as to avoid unnecessary damage. The system will observe the stack factor you have determined in product master or the stackability in forwarding/sales/purchase order item level and respect it.


Loading Sequence

By default, the generated load plan will also consider loading sequence, which means it will ensure the easiness of unloading packages/pallets without moving other pallets/products that will be delivered to next customer – so stop sequence is a key for efficient loading certainly.  To be more specific, since one truck may go to multiple destination, the packages/pallets which will be transported to the 1st destination will be placed nearest to the door, while the ones that go to the last destination would be located furthest to the door, so on so forth. But if you have activated the rule “Ignore last in first out (LIFO)”, then system may determine the load plan by omitting the loading sequence. In addition, the overall planning capabilities of SAP TM will combine this “equipment level” opportunities with broader overall optimization opportunities, inter-modal optimization, cross-docking and compartment planning if required.


Maximum Weight on Each Axle

Based on the Bridge Formula Weights Calculator published by U.S Department of Transportation, maximum allowable weight that any set of axles on a motor vehicle may carry on the Interstate highway system should be honored. Once you maintain this info as one of the physical properties for the vehicle in SAP Transportation Management, then system will take into account this factor when conducting load planning.


After minimizing the penalty costs of violating the key objectives under the given constraints, the system will generate a load plan. From the load plan, we could tell the loading sequence of each item. And using the stack, row, level and deck information, we could point out the exact position of the cargo item within the truck. Also, by running the optimizer, the system propose the orientation of loading the item, like, whether need to turn it to some other direction or not. 



Figure 1. Example of Load Plan in SAP TM


You can easily integrate this load plan with your SAP EWM - Extended Warehouse Management processes via out of the box process integration provided by SAP TM and SAP EWM in both directions; or by downloading the load plan into excel spreadsheets. This could be a simply way to share load plans e.g. with co-packers or low-tech service providers e.g. at cross docking locations or at the goods receipt side for customers addressing more detailed information for process customers and external business partners.

As mentioned earlier SAP Transportation Management (SAP TM) also provides visualization of the load plan. It allows us not only take a look at the load result through a table based load plan, but also illustrates the load layout for how each item gets loaded on the truck by viewing the 3D model, which is interactive, color coded and allows to move and change the viewers perspective on the model. And by hovering over the cursor on certain item, we get more details about it, like item numbers, destination, and weight etc.



Figure 2. Example of Load Plan 3D view in SAP TM



For illustration purposes let us take a very simple example. Suppose we have the following dimensions for the truck and each package:


Table 1. Size of a Truck and the Related Package for an Example


Given the weight capacity of this 20’ truck is 20,000 lbs while the weight for each package is 180 lbs, now assume we have 4 packages all go from source A to destination B on the same date. If just consider weight and volume, we can put these 4 packages on the same truck.

But what often happens in reality, you might be in a position of not being able to realize a load plan for various reasons, e.g. because of dimension constraints of the actual truck. So after load planning, you are able to easily unassign one package from the truck (referring to figure 3). You may then split the package into several (freight units), which allow you to adjust and finalize your adjustment process right away in the planning cockpit of SAP TM.



Figure 3. Loading Plan result for Example


Technical dependencies to setup load planning

Now that we are aware of the usefulness of load planning, then is it hard to realize this function? Actually, you just need a few steps.

First, we need maintain the load plan relevant attributes for both vehicle and cargo items. For example, the internal length, width, and height of the vehicle, axle type and position as well as the dimension for the cargo item are all load plan relevant attributes. The more accurate the data you have, the more realistic the plan will be.



Figure 4. Example of Vehicle Resource Info in SAP TM



Figure 5. Example of Product Info in SAP TM


Secondly, by leveraging SAP Visual Business, the transportation network could be shown in SAP Transportation Management (SAP TM) using a map. The same component, Visual Business 2.1 (or higher) is leveraged to realize the visualization of load plan in SAP TM.



Figure 6. Example of Map and Load Planning in SAP TM


Finally we need to define the load plan rules, like, stack height ascending in driving direction, or stack smaller package on top of larger one. So in the system, we have a lot of rules that could be used accordingly to differentiate and specify loading requirements.

Not to forget, the load builder is perfectly enhancing existing optimization capabilities of SAP TM, such as decreasing capacities, where you can define, that for every additional stop of a load, the de-facto capacity is getting lower, in order to reflect limitations such as the need to handle a lifter on a truck for example.



Figure 7. Example of Load Planning Rule in SAP TM


Besides the standard function that has been discussed here, there are also customized enhancement options for both process controller strategy and visualization. You can possibly determine pre-processing or post-processing steps when it’s necessary. For example, via enhancement, the unloaded item could be automatically unassigned from the freight order. And you can also display the cargo items by different color if you want to differentiate them via destination or other factors.

As you can see, this tool is very beneficial to the company that want to maximize the utilization of the truck with respect to the way they load it. By considering factors like dimension, stackability, loading sequence, orientation, or legal restriction, load planning enable the transportation plan to be more realistic.