Transportation Optimization model structure

For Transportation Optimization models, the following is a list of the tables you use to populate Transportation Optimization data:

Sites and Customers

When defining sites:

• For outbound consolidation, define at least one site where Type is Existing Site and at least one customer. For inbound consolidation, define at least two existing sites.
• Specify Latitude and Longitude values for each site/customer.
• If required, enter the Time Zone for the location. If no time zone is provided, the Time Zone defaults to EST (Eastern Standard Time). For guidelines about time zones, refer to Time Zones.
• If required, limit the radius distance from the site from which assets can originate using Asset Search Distance.
• Optionally, set the Fixed Service Time, Fixed Service Time Load, Fixed Service Time Unload, Variable Service Time Load and Variable Service Time Unload to account for handling time at the site.
• To represent both inbound and outbound shipments being served by one pool site, create two sites: one for the inbound pool site, and one for the outbound pool site. These sites can have identical Latitude and Longitude values.

Products

When defining products:

• Define at least one product. The shipments used for Transportation Optimization must include the product.
• Optionally define the product dimensions using Height, Length, and Width.

Shipments

You use the Shipments table to define the shipments used for vehicle routing.

• Define shipments with a Source Site and Destination Site.
• Shipments with the same pool site and mode are routed together. Shipments that do not have the same pool site and mode are not routed together, even if the sites are physically next to each other.
• Optionally define the shipment pickup and delivery windows. If you do not specify shipment pickup and delivery windows, Transportation Optimization uses the model horizon Start Date and End Date or the shipment window. For additional information, refer to Modeling shipment windows and business hours.

Transportation assets

Transportation assets define the type(s) of assets that Transportation Optimization can use. You use the Transportation Assets table to define the constraints of the asset, such as its speed, capacity, and the constraints on routing. You use the Asset Availability table to determine how many units of each asset are available at each pooling site.

• Define at least one transportation asset.
• Set the Capacity (Weight), Capacity (Volume), or Capacity (Quantity) as needed. If you do not provide capacity constraints, Transportation Optimization places no limit on how much an asset can hold per route.
• Optionally, set routing constraints on the asset, such as Max In-Transit Stops Per Route and Max Total Distance Per Route.
• Optionally, set constraints that apply based on regulations, such as Max Duty Time Before Rest Time and Max Drive Time Before Rest Time.
• Determine if the asset is required to travel round trip (Is Round Trip) and return to its origin.

If you are modeling electric vehicles, you will populate the Battery column, as well as records in related tables as described in Modeling electric vehicles.

Asset availability

You use the Asset Availability table to define the assets available at each site. You also use this table to define the time constraints per asset.

• Select the pooling or asset Site Name, then select the Asset Name of the asset available at the site. You can have multiple types of assets available at each site.
• Specify the Available Units of the asset at the site.
• If you are using Mode to control the pooling of your shipments, select the Mode for the asset. Only shipments with the same Mode are routed with this asset.
• Optionally specify the Start Date and End Date for the asset availability. If no values are entered for these fields, the asset if available for the full model horizon.

Rate

Define the detailed rate information used to cost your vehicle routes. You must define at least one rate. Rates can be based on distance and/or time. There are separate distance rates for loaded distance and the distance to reposition empty assets.

A number of the cost fields on the Rate table support step functions. For example, you can define a rate record in which the first stop is free, then each subsequent stop is charged at $75 per stop. The value of the Per Stop Cost is defined using a Step Cost Definition with associated Step Costs:

If the rate is not asset-specific, it can be used to cost all routes. You can select an Asset Name to make the rate asset-specific.

The Rate table includes fields that support discounts and surcharges, out of route distance costs, as well as a charge per stop on the route, and costs for drive, break, and waiting time. You can specify the names of an origin and destination location group if you are applying the rate to a group of locations. When you apply location group values, the Rate Type setting in Transportation Assets must be set to match.

Relationship constraints

The Relationship Constraints table enables you to define relationships between entities (sites, products, assets, or shipments) that must be forced or prevented when building routes.

In the Relationship Constraints table, you use the Status field to determine whether the relationship should be considered when solving the model. This is useful when running scenarios, such as quantifying cost difference in enforcing relationships. You use the Relationship field to force or prevent the relationship when creating routes.

The following combinations are supported:

If a combination has both prevent and force constraints applied, the prevent constraint overrides the force constraint.

Keep in mind that if the relationship constraints you create apply to one of a group of shipments from the same origin to the same destination, these shipments are combined prior to the optimization and they are treated, in effect, like one shipment. Therefore, a constraint on a single shipment is applied even if other shipments with the same origin and destination are not constrained.

The following examples show how the entities in a relationship can be affected by constraints:

Business hours

You can optionally define the business hours per day of the week per site using this table. If you do not define business hours, sites are considered to be open 24 hours a day, 7 days a week.

• Select the Site, then determine the open time and close time for each day of the week. The default open time is 00:00 (midnight) and the default close time is 23:59 (11:59 PM).
• You can define the time using a 24-hour clock (such as 18:30), or include the AM and PM designations when using a 12-hour clock (such as 6:30 PM).

For example, to define business hours for a pool site so that it is open from 6 AM to 3 PM Monday through Friday, you set the Open and Closed values for Sunday and Saturday to 00:00. The Open values for the weekdays (Monday through Friday) are 06:00 and the Closed values for the weekdays are 15:00.

Transit matrix

You can optionally define overrides to the calculated travel time or distance or both between pairs of locations. Additionally, you can define a Cost to override the cost calculated based on the defined rate records.

• Select an Origin and Destination site for the override.
• Specify the Distance and Travel Time to override the calculated values. The Travel Time is specified in days.
• Optionally specify a Cost if you want to override the calculated cost based on rates.
• Optionally apply the override to a specific Asset Name. In this way, you can have different travel times and distances based on the type of asset.
• Transit Matrix records default to being symmetric, meaning that the override applies if the travel is from Origin to Destination or from Destination to Origin. You can set Is Symmetric to No if the overrides vary based on the direction traveled.

Periodic schedule

You create the allowable schedules for the sites in the Periodic Schedule table. In the Periodic Schedule table, you can provide the inventory holding cost, maximum drop size and capacity at customer locations. You can also define the frequency of deliveries over the model horizon and the minimum and maximum number of days between visits. These values are specified per location. Additionally, you can force which days in the horizon must be used and which days cannot be used for visits.

Hubs

When using Hub Optimization, you use the Hubs table to identify which sites can be used as hubs for shipments. You can use groups to specify the sites and shipments. Additionally, this table provides fields to define:

• The minimum time that a shipment must stay at the hub and the maximum time that it is allowed to stay at the hub.
• The cost to ship directly to or from the hub.
• The time required to ship directly to or from the hub.