In supply chains, it’s common to record the moment when something is first created, introduced or made traceable - this could be:
  • Harvesting grain from a paddock.
  • Marking livestock for the first time.
  • Manufacturing a batch of product (like cans of tuna, or pallets of flour)
In EPCIS, these creation moments are usually modeled using an ObjectEvent with:
  • action set to ADD
  • epcList or quantityList containing the identifier of the products that were created.
  • and often accompanied by a bizStep like commissioning or receiving depending on context.

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Product Identifiers

At the end of a commissioning event, we need unique identifiers for the products that were created. The TrustStack supports master data concepts such as Trade Items. As a refresh, a Trade Item is anything that can be priced in sold in a supply chain. We can reference a TradeItem when creating a Event to generate a unique identifier for the product.

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Example

Let’s say we are building a grain farm management application, and we need users to be able commission a batch of wheat. Such as, the farmer has harvested a paddock of wheat, and we need to create a unique identifier for the batch wheat.

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Farm and Paddock

Let’s use the TrustStack SDK to create a new Farm and Paddock for our example. 
import {TrustStack} from "@truststack/sdk";

const truststack = new TrustStack({
  apiKey: "your-api-key",
});

const farm = await truststack.masterData.createFarm(
  {
    name: "Farm 1",
  },
  {organizationId: "farm-organization-id"}
);

const paddock = await truststack.masterData.createPaddock(
  {
    name: "Paddock 1",
    parentLocationId: farm.id,
  },
  {organizationId: "farm-organization-id"}
);
We now have a Farm and Paddock in the TrustStack for this farming enterprise.

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Wheat Trade Item

This farmer is harvesting Wheat, this can be priced and sold in the supply chain, so it is a TradeItem. Let’s create a TradeItem for Wheat. 
const wheat = await truststack.masterData.createTradeItem(
  {
    name: "Wheat",
  },
  {organizationId: "farm-organization-id"}
);

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Harvest Event

Now, the farmer has harvested the wheat from the paddock, and we need to create an event to record this. 
const harvestEvent = await truststack.event.createEvent(
  {
    action: "ADD",
    eventType: "OBJECT_EVENT",
    eventTime: new Date(),
    bizStep: "COMMISSIONING",
    disposition: "ACTIVE",
    readPoint: {
      location: paddock.id,
    },
    quantityList: [
      {
        tradeItem: wheat.id,
        quantity: 10000,
        unit: "KGM",
      },
    ],
  },
  {organizationId: "farm-organization-id"}
);

console.log(harvestEvent);
The output of this event will be: 
{
  "id": "123e4567-e89b-12d3-a456-426614174000",
  "eventTime": "2021-01-01T00:00:00.000Z",
  "eventType": "OBJECT_EVENT",
  "bizStep": "COMMISSIONING",
  "disposition": "ACTIVE",
  "readPoint": {
    "location": "<PADDOCK-ID>"
  },
  "quantityList": [
    {
      "tradeItem": "XXXX.1.1",
      "quantity": 10000,
      "unit": "KGM"
    }
  ]
}
An event has now been created:
  • The readPoint is the paddock that the wheat was harvested from.
  • The quantityList contains a batch/lot level identifier of the Wheat TradeItem that was harvested, and the quantity harvested.
  • The eventTime is the date and time the harvest event occurred.
  • The bizStep is the business step of the harvest event, in this case COMMISSIONING.
  • The disposition is the disposition of the event, in this case ACTIVE.