CX-0122 Item Stock Exchange 2.0.0
ABSTRACT
The raising and management of Item Stock data is the task of ERP systems. Accurate inventory management is a decisive factor for stable delivery capability for suppliers and an important component of secure production capability for customers. Continuous monitoring of the Item Stock between suppliers and customers ensures important information for the company's own production planning and management. This information exchange is key to early detect and evaluate supply shortage issues. Moreover, standardized interfaces between ERP systems often exist only for order planning and execution. However, the necessary exchanging this information manually e.g. by phone or e-mail is error-prone and slow. To mitigate inefficient and faulty communication, this document defines a standardized approach for exchanging Item Stock data in an interoperable manner. A common description of the Item Stock based on a standardized semantic definition is fundamental for facilitating such an exchange.
FOR WHOM IS THE STANDARD DESIGNED
COMPARISON WITH THE PREVIOUS VERSION OF THE STANDARD
Changes:
- integration and usage of digital twins as defined in [CX-0002] Digital Twins in Catena-X
- harmonization of aspect model in accordance with [CX-0126] Industry Core: Part Type
- discontinuation of the proprietary API used in v1.0.0 of this standard
- grammatical, spelling and semantic improvements
New Content:
- added a note on the obligation of standard implementers to make aware that sensitive data is being handled, see [Chapter 2.1.3]
1 INTRODUCTION
This document defines the standardized exchange of Item Stock data within the Catena-X network. The Item Stock semantically is the actual quantity of reserved (here called allocated) material for a partner that has not yet been shipped from the supplier's site or has already arrived at the customer's site and has not yet been used for production. The semantic model is presented in the Aspect Model Notation with all individual fields, formats and associated JSON schema. The standardization of the ItemStock semantic model and an exchange API enables participants in the value chain to share information about material and product stock in a timely manner, thus ensuring that the possible solution space for mitigating a supply shortage is maximized.
The Item Stock is related to a business relationship between the partners (an order / call-off exists). Legal framework conditions and business aspects play an important role, for example in the context of multi-sourcing, where no horizontal exchange of information may take place. The aim of this standard is to ensure a secure exchange of stock data for active monitoring and the associated prevention of bottlenecks and shortages.
1.1 AUDIENCE & SCOPE
This section is non-normative
This standard is relevant for the following roles defined in [CX-OMW]:
- Data Providers willing to provide Item Stock data
- Data Consumers interested in requesting and receiving Item Stock data
- Business Application Providers interested in providing solutions implementing this standard
- Consulting Services Providers interested in supporting companies fulfilling the standard
The scope of this standard is only the Item Stock aspect model and API. It describes the exchange of Item Stock data through a connector in accordance to [CX-0018].
1.2 CONTEXT AND ARCHITECTURE FIT
This section is non-normative
A typical order-based procurement process includes a customer that places an order and a supplier fulfilling it. Material may be either on stock at the supplier's site when it has been produced and is ready to be shipped to the customer, or at the customer's site when it has been delivered and has not yet been used for production. Those kinds of inventories are referred to as Item Stock. Information about Item Stock quantities it is key to early detect and evaluate short-term supply shortages on the customer or supplier side. Also it can help reduce the total amount of stored material within the supply chain when partners share information on their materials inventory.
Figure 1 shows the high-level architecture of the Item Stock exchange in the Catena-X dataspace and the services that are involved. Both the data provider and the data consumer must be members of the Catena X network in order to communicate with each other. With the help of the Credential Service and the Identity Access Management (IAM) each participant can authenticate itself, verify the identity of the requesting party and decide whether to authorize the request. The Item Stock data is provisioned in accordance with [CX-0002].
Figure 1: High-level architecture of the Item Stock exchange in Catena-X
1.3 CONFORMANCE AND PROOF OF CONFORMITY
This section is non-normative
The sections marked as non-normative, all authoring guidelines, diagrams, examples, and notes in this specification are non-normative. Everything else in this specification is normative. The key words MAY , MUST , MUST NOT , OPTIONAL , RECOMMENDED , REQUIRED , SHOULD and SHOULD NOT in this document are to be interpreted as described in [BCP 14] [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
All participants and their solutions will need to prove that they are conform with the Catena-X standards. To validate that the standards are applied correctly, Catena-X employs Conformity Assessment Bodies (CABs). The proof of conformity for a single semantic model is done according to the general rules for proving the conformity of data provided to a semantic model or the ability to consume the corresponding data. Furthermore participants agree to follow the normative language of this standardization document and to implement the required API-Endpoints described in Chapter 4.
1.4 EXAMPLES
The following example shows a value-only JSON serialization of the "ItemStock" aspect model. It represents a quantity of 20 pieces for an order position of a given material.
{
"materialGlobalAssetId" : "urn:uuid:48878d48-6f1d-47f5-8ded-a441d0d879df",
"positions" : [ {
"orderPositionReference" : {
"supplierOrderId" : "M-Nbr-4711",
"customerOrderId" : "C-Nbr-4711",
"customerOrderPositionId" : "PositionId-01"
},
"allocatedStocks" : [ {
"isBlocked" : false,
"stockLocationBPNA" : "BPNA1234567890ZZ",
"lastUpdatedOnDateTime" : "2023-04-28T14:23:00.123456+14:00",
"quantityOnAllocatedStock" : {
"value" : 20.0,
"unit" : "unit:piece"
},
"stockLocationBPNS" : "BPNS1234567890ZZ"
} ]
} ],
"direction" : "INBOUND"
}
1.5 TERMINOLOGY
This section is non-normative
Name | Abrv. | Description |
---|---|---|
Business Partner Number | BPN | A BPN is the unique identifier of a partner within Catena-X as defined in [CX-0010]. |
Business Partner Number Legal Entity | BPNL | A BPNL is the unique identifier of a partner legal entity within Catena-X as defined in [CX-0010]. |
Business Partner Number Site | BPNS | A BPNS is the unique identifier of a partner site within Catena-X as defined in [CX-0010]. |
Business Partner Number Address | BPNA | A BPNA is the unique identifier of a partner address within Catena-X as defined in [CX-0010]. |
Position | A position within an order defines the product and the quantity the supplier has to manufacture / supply for a customer. A single order may contain multiple positions for different products. | |
Order | Request from a customer towards a supplier to manufacture / supply a given quantity of a specific product in a predefined time frame. | |
Allocated Stock | The already manufactured and not yet been used products, components or material. They are allocated to a specific customer based on the orders made by the latter and are either still in the supplier's warehouse or already in the customer's warehouse. | |
Provider | The party providing the Item Stock data.In the context of the Item Stock exchange this is: - the supplier for Item Stock of direction OUTBOUND - the customer for Item Stock of direction INBOUND. | |
Consumer | The party requesting and consuming the Item Stock data provided by the provider. In the context of the Item Stock exchange this is: - the supplier for Item Stock of direction OUTBOUND - the customer for Item Stock of direction INBOUND. Additional terminology used in this standard can be looked up in the glossary on the association homepage. | |
Stock Location | The physical location of a stock specified by its corresponding BPNS and BPNA. More information on BPN/S/A is provided in [CX-0010]. | |
Customer | The recipient of products ordered from / manufactured by a supplier. | |
Supplier | The supplier / manufacturer of a product. | |
Stock | Two way direction of material on stock: - One can have a stock of material which is ready for delivery to customers - One can have a stock of material which can be used for the own production | |
Material | The term material is used as a catalogue item in the meaning of the Industry Core Part Type ([CX-0126]). Whenever referring to material also products, components or items are considered. Semi-finished goods are not intended to be covered. | |
Production Output | The output quantity in a defined period of time for a component or material. | |
Digital Twin | DT | Digital representation of an asset that provides data on aspects of the represented data following [CX-0002]. |
decentralized Digital Twin Registry | dDTR | Component providing registration and discovery API implementations following [CX-0002]. Sometimes referred to without the "decentralized" BUT in Catena-X those are always decentralized. |
Asset Administration Shell | AAS | Technical concept for Digital Twins consisting of different standards. Application in Catena-X is described in Digital Twins in Catena-X standard ([CX-0002]) |
Shell Descriptor | Technical concept of the AAS API describing metadata of an Asset Administration Shell representing a Digital Twin. It holds identification information and metadata about which submodels are available and where to get the data from (see [CX-0002], IDTA-01002-3-0). There may exist multiple Shell Descriptor for the same represented Asset (see [CX-0126]). | |
Submodel Descriptor | Technical concept of the AAS API describing metadata of Submodels within a Shell Descriptor (Asset Administration Shell) (see [CX-0002], IDTA-01002-3-0). | |
Specific Asset Ids | Identifiers of the Shell Descriptor (Asset Administration Shell) that refer to common identification data for an asset/material at hand e.g., manufacturer part Id. Common specific asset ids used for identification are described in Industry Core Part Type Standard (see [CX-0126]). | |
Asset Administration Shell Identifier | AAS ID | Also referred to as Shell Descriptor ID, is the technical identifier of the Shell Descriptor. |
Global Asset Id | Also referred to as Catena-X ID, is the Catena-X identifier for assets represented by Digital Twins (see [CX-0126]). | |
Aspect | A domain-specific view on information and functionality associated with a specific Digital Twin with a reference to a concrete Aspect Model (see [CX-0002]). Within Catena-X, an aspect is formally described using the Semantic Aspect Meta Model (see [CX-0003]). | |
Semantic Id | Identifier including namespace to specify the semantic description of submodels using the Semantic Aspect Meta Model (SAMM). It allows partners to know the exact data format and semantics when e.g., browsing catalogs (see [CX-0003]). | |
Data Space Protocol | DSP | A set of specifications designed to facilitate interoperable data sharing between entities governed by usage control and based on Web technologies. These specifications define the schemas and protocols required for entities to publish data, negotiate Agreements, and access data as part of a Dataspace. It is governed by the International Data Spaces Association. Connectors compliant to [CX-0018] support the Data Space Protocol. |
Shared Asset Approach | Digital twin pattern in which each party has a twin for the same asset (Part Type). They share the same identification data in terms of specific asset ids and global asset id. The digital twins do have different technical identifiers. |
Table 1: Terminology Item Stock Standard
Additional terminology used in this standard can be looked up in the glossary on the association homepage.
2 RELEVANT PARTS OF THE STANDARD FOR SPECIFIC USE CASES
This section is normative
2.1 "ITEM STOCK"
2.1.1 LIST OF STANDALONE STANDARDS
The following Catena-X standards are prerequisites for the implementation of this standard and therefore MUST be considered / implemented by the relevant parties specified in each of them.
Number | Standard | Version |
---|---|---|
[CX-0001] | EDC Discovery API | 1.0.2 |
[CX-0002] | Digital Twins in Catena-X | 2.2.0 |
[CX-0003] | SAMM Aspect Meta Model | 1.1.0 |
[CX-0006] | Registration and initial onboarding | 2.0.0 |
[CX-0010] | Business Partner Number (BPN) | 2.0.0 |
[CX-0018] | Dataspace Connectivity | 3.0.0 |
[CX-0126] | Industry Core Part Type | 2.0.0 |
Table 2: List of mandatory standards
The usage of this standard may be complemented with the following Catena-X standards to further extend the range of shortage prevention possibilities:
Number | Standard | Version |
---|---|---|
[CX-0118] | Delivery Information Exchange | 2.0.0 |
[CX-0120] | Short-term Material Demand Exchange | 2.0.0 |
[CX-0121] | Planned Production Output Exchange | 1.0.0 |
[CX-0145] | Days of Supply Exchange | 1.0.0 |
[CX-0146] | Supply Chain Disruption Notifications | 1.0.0 |
Table 3: List of non-mandatory complementary standards
2.1.2 DATA REQUIRED
No additional data requirements.
2.1.3 ADDITIONAL REQUIREMENTS
CONVENTIONS FOR USE CASE POLICY IN CONTEXT DATA EXCHANGE
In alignment with our commitment to data sovereignty, a specific framework governing the utilization of data within the Catena-X use cases has been outlined. A set of specific policies on data offering and data usage level detail the conditions under which data may be accessed, shared, and used, ensuring compliance with legal standards.
For a comprehensive understanding of the rights, restrictions, and obligations associated with data usage in the Catena-X ecosystem, we refer users to
- the detailed ODRL policy repository [CX-ODRL]. This document provides in-depth explanations of the terms and conditions applied to data access and utilization, ensuring that all engagement with our data is conducted responsibly and in accordance with established guidelines.
- the ODRL schema template. This defines how policies used for data sharing/usage should get defined. Those schemas MUST be followed when providing services or apps for data sharing/consuming.
ADDITIONAL DETAILS REGARDING ACCESS POLICIES
A Data Provider may tie certain access authorizations ("Access Policies") to its data offers for members of Catena-X and one or several Data Consumers. By limiting access to certain Participants, Data Provider maintains control over its anti-trust obligations when sharing certain data. In particular, Data Provider may apply Access Policies to restrict access to a particular data offer for only one Participant identified by a specific business partner number.
- Membership
- BPNL
ADDITIONAL DETAILS REGARDING USAGE POLICIES
In the context of data usage policies (“Usage Policies”), Participants and related services MUST use the following policy rules:
- Use Case Framework (“FrameworkAgreement”)
- at least one use case purpose (“UsagePurpose”) from the above mentioned ODRL policy repository.
Additionally, respective usage policies MAY include the following policy rule:
- Reference Contract (“ContractReference”).
Details on namespaces and ODRL policy rule values to be used for the above-mentioned types are provided via the ODRL policy repository [CX-ODRL].
REMINDER OF ANTITRUST
Notice and/or acknowledgement concepts to raise awareness of antitrust issues during use of this standard are RECOMMENDED, for example through the implementation of a help desk or pop-up info.
2.1.4 DIGITAL TWINS AND SPECIFIC ASSET IDs
This standard builds upon the Industry Core Part Type [CX-0126] and the Digital Twins in Catena-X [CX-0002] standards. It follows the following design patterns:
- Usage of Digital Twins as shared assets to follow a pull approach for data.
- Usage of the specific asset IDs and further identification data for the Digital Twin for the Part Type (see [CX-0126]).
- Provisioning of the PartTypeInformation on supplier side (see [CX-0126]).
Because both parties may provide data regarding different aspects of the same Part Type Twin, they need to use the same identification data to pinpoint it.
- The supplier of the part has a Digital Twin representation and is then able to offer Item Stock data to customers.
- The customer, who orders or uses the part, has a Digital Twin representation to offer Item Stock data to a supplier.
- Both twins refer to the same asset and provide complementary information. They share the same
identification data in two partners' context.
- The supplier
- MUST create the Digital Twin first.
- MUST generate the Catena-X ID and ensure that the customer-specific asset IDs and submodel descriptors are only accessible by the specific customer.
- MAY use the Digital Twin for multiple customers.
- The customer
- MUST create one Digital Twin per supplier.
- MUST use the Catena-X ID generated by the supplier.
- The supplier
The definition of identification data (Catena-X ID, Asset Administration Shell ID, specific asset ID) MUST follow the Industry Core Part Type [CX-0126]. Refer to Chapter 4.1.2 for further details.
Note: The Part Type Twin's data is considered sensitive. Data providers MUST implement appropriate measures ensuring that competitors-specific asset IDs and/or information about submodels is accessible only to the data consumers it concerns, but not to their competitors.
Figure 2 shows how the shared asset approach is realized. The orange lines show which submodels belong to the respective AAS. All Item Stock specific submodels are bound to the specific Part Type's context e.g., meaning that the Item Stock aspect is described for the specific catalog item on supplier and customer side represented by the AASs. The orange submodels are the submodels used within this standard's context. The grey submodels are used within the Industry Core [CX-0126](PartTypeInformation, SingleLevelBomAsPlanned, SingleLevelUsageAsPlanned). The blue dashed lines show the references between DTs based on Catena-X UUIDs and BPNL information that may be resolved by the Item Relationship Service (see [CX-0126]).
Figure 2: Conceptual levels of provisioning digital twins in the shared asset approach.
Figure 2 details two conceptual levels:
- The Asset level contains the asset (Industry Core Part Type) represented by a Digital Twin. The latter is provisioned as an Asset Administration Shell (AAS) within the decentralized Digital Twin Registry (dDTR) of the data provider (supplier or customer).
- The Submodel level represents the actual information that are held by a Digital Twin (DT). Those submodels follow the respective definition of the in Semantic Aspect Meta Model (SAMM) format (see Chapter 3). The dDTR only holds meta-information about the Submodel (e.g. kind of submodel via semantic ID or connector endpoint information).
3 ASPECT MODELS
This section is normative