Network Inventory Summary

Internal Table Name: OptimizationOutputInventory

This output table summarizes end inventory and associated costs per site. In-transit inventory for Production (work in progress at the site) is reported in this table. Transportation-based in-transit inventory is reported in the InterSite Flows table.

Scenario

Table: OptimizationOutputInventory

Internal Name: Not Applicable (Scenario column not in table)

The scenario for which the summary data was generated.

Site Name

Table: OptimizationOutputInventory

Internal Name: SiteName

The name of the site that holds inventory.

Product Name

Table: OptimizationOutputInventory

Internal Name: ProductName*

The name of the product stocked at this site.

Organization Name

Table: OptimizationOutputInventory

Internal Name: OrganizationName

The Organization to which the inventory is allocated. When the inventory is associated with Sites that belong to the Organization, the inventory is attributed to the Organization as required.

Period Name

Table: OptimizationOutputInventory

Internal Name: PeriodName

The name of the period to which these inventory statistics apply.

Pre Build Inventory

Table: OptimizationOutputInventory

Internal Name: PreBuildInventory

The amount of inventory held ahead of the demand period to ensure against known demand seasonality. Production capacity constraints in a period can place limits on production that prevent demand from being met in peak periods. If production capacity in earlier model periods is available, and minimum and maximum inventory constraints permit it, pre-build inventory can be accumulated to meet the demand in a peak period. When the Safety Stock column in Inventory Constraints is set to "Include", there can be positive Safety Inventory or Pre Build Inventory (or both) in the solution. If the inventory is reported as Pre Build Inventory rather than Safety Inventory, the objective value will not change.

Period No

Table: OptimizationOutputInventory

Internal Name: PeriodNo

The sequence number for the period. This value is useful when sorting periods sequentially rather than by name.

Transportation Safety Stock

Table: OptimizationOutputInventory

Internal Name: TransportationSafetyStock

Displays any safety stock held in transportation. Safety stock can be held as a result of transportation lead time variability. For example, if you define a Transport Time of N(10,5), the standard deviation of lead time (S_L) is 5 as defined in Transportation safety stock. This amount is separate from the safety stock quantity at the destination.

Transportation Safety Stock Cost

Table: OptimizationOutputInventory

Internal Name: TransportationSafetyStockCost

The cost of any Transportation Safety Stock based on the Inventory Carrying Cost in Model Settings.

Safety Inventory

Table: OptimizationOutputInventory

Internal Name: SafetyInventory

The buffer stock accumulated to avoid stock outs. Network Optimization determines this value based on the Safety Stock and Safety Stock Basis fields in Inventory Policies.

• When the basis is Quantity, the Safety Inventory for a given product at a site is equal to the Safety Stock defined in the Inventory Policies table.
• When the basis is DOS (Days of Supply), the Safety Inventory = (days of supply) * (outflow per day of the product)
  • The Safety Stock column represents the days of supply.
  • The outflow per day is also impacted by the model horizon.

When the Safety Stock column in Inventory Constraints is set to "Include", there can be positive Safety Inventory or Pre Build Inventory (or both) in the solution. If the inventory is reported as Pre Build Inventory rather than Safety Inventory, the objective value will not change. The solution can also have positive Safety Inventory if you populate the Safety Stock column in Inventory Policies with a positive value.

Cycle Stock

Table: OptimizationOutputInventory

Internal Name: CycleStock

The stock allocated to meet immediate forecasted demand. The production Cycle Stock is calculated as:

(0.5 * Minimum Order Quantity) * 1 if production, else 0 if no production

Replenishment Cycle Stock can also be generated when you have a Replenishment Frequency:

Max(((Replenishment Frequency * Flow)/days in period),Min Order Quantity)/2

For additional details about both production and replenishment Cycle Stock, see Cycle Stock Optimization.

Turn Estimated Inventory

Table: OptimizationOutputInventory

Internal Name: TurnEstimatedInventory

The number of units of inventory expected per inventory turn.

Turn Estimated Inventory = (number of flow units) / (number of turns)

Total Inventory

Table: OptimizationOutputInventory

Internal Name: TotalInventory

The total units of product held during the optimization run.

Total Inv Holding Cost

Table: OptimizationOutputInventory

Internal Name: TotalInvHoldingCost

The cost for inventory of the product at the end of the period at this site. This field is only listed for multi-time period models.

The Total Inv Holding Cost is calculated as:

=Total Facility Inventory Cost + Total WIP In-Transit Inventory Cost, or

= (Total Ending Inventory + Cycle Stock + Turn Estimated Inventory + Transportation Safety Stock + WIP In-Transit Inventory) * Unit Inventory Cost

where:

Unit Inventory Cost = Product Unit Value * Inv Carrying Cost % * (Period Length / 365) + Unit Storage Cost

The WIP In-Transit Inventory is work in progress inventory based on Production only.

If the Inv Carrying Cost % is populated in Inventory Policies, this value is used; otherwise the Inventory Carrying Cost % from Model Settings is used.

For example, assume the following data in a model with two 6-month periods of lengths 181 and 184 days respectively:

• Quantity = 100 in each period (Customer Demand table)
• Unit Value = 2 (Products table)
• Unit Storage Cost = 1 (Inventory Policies table)
• Inventory Carrying Cost = 12% (Model Settings)

When Network Optimization is run, the output is as follows:

For Period_001:

Scheduled Receipt

Table: OptimizationOutputInventory

Internal Name: ScheduledReceipt

The total beginning inventory for the Site-Product-Period combination.

Total Ending Inventory

Table: OptimizationOutputInventory

Internal Name: TotalEndingInventory

The total number of units remaining at the end of the model run time.

Total Ending Inv Holding Cost

Table: OptimizationOutputInventory

Internal Name: TotalEndingInvHoldingCost

The cost for inventory of the product at the end of the period at this site.

The Total Ending Inv Holding Cost is calculated as:

= Total Ending Inventory * Unit Inventory Cost

where:

Unit Inventory Cost = Product Unit Value * Inv Carrying Cost % * (Period Length / 365) + Unit Storage Cost

If the Inv Carrying Cost % is populated in Inventory Policies, this value is used; otherwise the Inventory Carrying Cost % from Model Settings is used. Unit Storage Cost is defined in Inventory Policies.

Work In Progress Inventory

Table: OptimizationOutputInventory

Internal Name: InTransitInventory

The amount of product that is inaccessible because it is work in progress at the site. The inventory is based on Production. This is calculated as:

Work In Progress Inventory = (production flow * min(Fixed Order Time, time remaining in the model horizon)) / (2 * period length in days)

where:

production flow is the Gross Production Quantity from the Production Flows table

period length is the number of days in the current period

Fixed Order Time (in days) is from the Production Policies table.

Transportation-based in-transit inventory is reported in the InterSite Flows table.

Excess Inventory

Table: OptimizationOutputInventory

Internal Name: ExcessInventory

The units of inventory held in excess of the safety stock.

Scenario ID

Table: OptimizationOutputInventory

Internal Name: ScenarioID

The identifier of the scenario for which the summary data was generated.

Sub-Scenario ID

Table: OptimizationOutputInventory

Internal Name: StepNumber

The identifier of the sub-scenario, if applicable, for which the summary data was generated.