Ready to Get Started With NIEM?
NIEM is the result of a collaborative effort to produce a set of common, well-defined data elements to be used for development and . NIEM was designed as a set of building blocks that are used as a consistent baseline for creating exchange documents and transactions across government so that the sender and receiver of information share a common, unambiguous understanding of the meaning of that information. Conformance to NIEM ensures that a basic set of information is well understood and carries the same consistent meaning across various communities, thus allowing interoperability to occur.
To begin exchanging information, information exchange partners must first develop a data exchange. In NIEM, a “data exchange” is also known as an Information Exchange Package (), a description of specific information exchanged between a sender and a receiver. The IEP is usually coupled with additional documentation, sample instances, business rules, and more to compose an Information Exchange Package Documentation (). An IEPD is the final product of the NIEM exchange development process, also known as the
IEPD Lifecycle.
NIEM uses Extensible Markup Language (XML) for schema definitions and element representation, which allows the structure and meaning of data to be defined through simple, but carefully defined XML syntax rules. This provides a common framework for information exchange.
How do I…?
Please click on the questions below, as needed, to assist in your NIEM understanding and technical development. If you have a question related to exchange development that is not addressed below or in our help desk knowledgebase, please contact us!
- How do I find an existing exchange?
- How do I build an exchange?
- How do I search the model?
- What are the Naming and Design Rules?
- How do I build an extension?
- What tools are available?
- What are the rules for NIEM Conformance?
- How do I share my IEPD for reuse?
- What is Model Package Description?
- What training is available?
- How do I engage with NIEM?
How do I find an existing exchange?
Because the Extensible Markup Language ()-based NIEM data model is composed of data components that cross sectors, functions, and geographic boundaries, an exchange developed for one organizational business requirement could be reused, partially or fully, for a different need within that organization or another.
NIEM.gov promotes information exchange reuse through the Work with IEPDs tool, found in the tools catalog, which allows users to search existing for reuse. Additionally, the IEPD Clearinghouse is an interactive repository website that provides government and industry IT professionals with information about planned, in-progress, and completed IEPD initiatives. Public and private developers can maximize resources and time by using the Work with IEPDs tool and the IEPD Clearinghouse to gain access to NIEM-conformant reusable . Funding agencies, policy makers, and managers can avoid duplicative efforts by using these tools to research in-progress IEPD development initiatives. Most importantly, the IEPD Clearinghouse enables directly relevant collaboration between organizations and people working to solve similar problems within the justice and public safety communities.
While the IEPD Clearinghouse provides descriptive information about IEPDs, it does not contain the actual IEPDs and their associated artifacts (such as documents and ). To locate and download the actual IEPDs and artifacts, refer to the website listed under each IEPD information article.
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How do I build an exchange?
To begin exchanging information, information exchange partners must first develop data exchanges, also known as Information Exchange Packages (), which are then documented as .
A user builds an IEPD from business requirements in order for the IEPD to include both business and technical that define the cross-boundary information exchange taking place between multiple parties. For example, there are technical schemas that define the specific data being exchanged, as well as non-technical documents that capture information such as business rules and context
The NIEM IEPD Lifecycle has six phases:
- Scenario Planning: Enables the identification of scenarios requiring the exchange of information, business requirements, and business context.
- Analyze Requirements: Defines the business and data requirements associated with a NIEM information exchange.
- Map and Model: Comprises activities focused on creating the exchange model, then mapping it to the NIEM model.
- Build and Validate: Focuses on the creation of a set of NIEM-conformant XML schemas that implement the document structure identified in the previous steps.
- Assemble and Document: Concentrates on assembling all artifacts of the IEPD, and completing any remaining documentation.
- Publish and Implement: Focuses on publishing the IEPD, and using it in a production mode.
NIEM-conformant IEPDs follow the Model Package Description (MPD) Specification, which requires that and instance documents contained within the IEPD are NIEM-conformant, and describes additional requirements for a collection of artifacts to comprise an IEPD.
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How do I search the model?
Upon identification of information exchange requirements, the process of mapping data elements to NIEM requires developers to search through the model to identify semantic equivalent elements between an organization’s data set and the NIEM model. There are a number of ways to explore the model to aid this process: the Data Model Browser; several alternate model formats, such as spreadsheets and a database; the Subset Schema Generation Tool (SSGT); and third party toolsets.
The NIEM architecture consists of two sets of vocabularies—NIEM Core and the individual NIEM domains. NIEM Core includes “universal” components, concepts that are commonly understood across all (or the majority of) NIEM domains, such as person, activity, date, time, and location. The individual NIEM domains contain mission-specific data components that build upon concepts in NIEM Core.
The current NIEM release can be found here.
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What are the NIEM Naming and Design Rules?
The NIEM Naming and Design Rules (NDR) specifies rules and requirements of developed for NIEM and guarantees conformance to those that follow them. The NDR is intended to ensure interoperability even when different developers are building independently. The NDR:
- Describes the underlying NIEM data model.
- Describes guiding principles of NIEM design.
- Defines rules for using constructs in NIEM.
- Defines rules for modeling and structuring NIEM-conformant schemas.
- Defines rules for naming and extending NIEM components.
Sections relevant to IEPD development include:
- Section 2.3, IEPD Subset Schemas
- Section 2.4, IEPD Extension Schemas and Exchange Schemas
- Section 2.5, IEPD Constraint Schemas
- Section 2.6, NIEM-conformant XML Documents and Elements
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How do I build an extension?
In many cases, an will require data structures that do not exist in NIEM. These structures are identified in the Map and Model step of the IEPD Development Lifecycle (see above) since they will not map to anything in NIEM. Such structures should be defined in an extension
Extension schemas are a mechanism to create reusable local components in the exchange schema. If a local component is expected to be used only in a single exchange, it may be defined in the exchange schema. If the local component is expected to be used in multiple exchanges, it can be defined once in the extension schema and reused (by importing and referencing) in the various exchange schemas. This is often simpler than defining and keeping track of the component in each exchange schema in which it is used.
The extension schema defines an IEPD-specific namespace (sometimes called a “local” namespace). Because the types and elements in an IEPD-specific namespace are not part of NIEM, there is no equivalent of the for extension schemas. Extension schemas must generally be developed from scratch by writing XML schema constructs.
It is recommended that every type in an extension schema extend some type in NIEM (even if it only extends ComplexObjectType, ReferenceType, or AugmentationType). Extending NIEM types fosters reuse of NIEM’s semantics, enforcing consistency of objects. To make NIEM namespace types (and elements) available in an extension schema, the extension schema must import the schemas for the appropriate NIEM namespaces. If the extension schema uses other namespaces within NIEM (e.g., a codelist namespace) or outside NIEM, it must import schemas that define those namespaces as well.
After reviewing the NIEM data model, you may find that the concept to be represented in an information exchange does not exist in NIEM. In this case, NIEM provides three techniques for creating new NIEM types to represent new concepts:
- Composing a new NIEM type from a collection of NIEM properties.
- Extending an existing NIEM type to create a new NIEM type.
- Augmenting an existing NIEM type to create a new NIEM-derived type.
Techniques for Building and Extending NIEM XML Components discusses the key NIEM data model concepts. In addition, it outlines the basic techniques for extending and augmenting NIEM provided data components in order to create meaningful links between new and existing data items, and adapts external standards for use in the NIEM framework.
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What tools are available?
Designed for informational purposes and convenience of the NIEM community, web-based and stand-alone tools, provided in the tools catalog, either assist in the creation of for or facilitate the understanding of at least one of the five Model Package Description (MPD) classes: release, update,, EIEM, and core update. The tools catalog is your one-stop-shop for every NIEM tool available.
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What are the rules for NIEM Conformance?
The rules for NIEM conformance are as follows:
- Instances must validate against NIEM reference which are available at http://release.niem.gov or within the Subset Schema Generator Tool available in the tools catalog. Schemas conformant to NIEM must import and reference the relevant NIEM schema namespaces (i.e. Core, Justice, International Trade, Maritime, etc.).
- If the appropriate component (i.e.type, element, attribute, etc.) required for an IEPD exists in the NIEM data model, use that component. Do not create a duplicate component if one already exists.
- Be semantically consistent. Use NIEM components in accordance with their definitions. Do not use a NIEM element to encapsulate data other than what its definition describes.
- Follow the IEPD (Information Exchange Package Documentation) Lifecycle and define artifacts at each step as required by the Model Package Description Specification.
- Adhere to the NIEM Naming and Design Rules (NDR) to ensure correct, consistent schema development.
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How do I share my NIEM exchange for reuse?
Developing and implementing NIEM-conformant exchanges allows organizations to leverage existing information system investments, as NIEM enables different information systems to share and exchange information irrespective of technologies. Creating and adopting NIEM-conformant exchanges means that local, state, tribal, and federal organizations can reap significant cost benefits through adoption and reuse, rather than building proprietary, single-use software from scratch.
NIEM.gov promotes information exchange reuse through the Work with IEPDs tool, found in the tools catalog. Additionally, the IEPD Clearinghouse is an interactive repository website that provides government and industry IT professionals with information regarding planned, in-progress, and completed initiatives.
Public and private developers can maximize resources and time by using the Work with IEPDs tool and the IEPD Clearinghouse to gain access to NIEM-conformant reusable . Funding agencies, policy makers, and managers can avoid duplicative efforts by researching in-progress IEPD development initiatives. Most importantly, the IEPD Clearinghouse enables directly relevant collaboration between organizations and people working to solve similar problems within the justice and public safety communities.
While the IEPD Clearinghouse site provides descriptive information about IEPDs, it does not contain the actual IEPDs and associated artifacts (such as documents and ). To locate and download the actual IEPDs and artifacts, refer to the website listed under each IEPD information article. The IEPD Clearinghouse can be accessed at http://it.ojp.gov/iepd/.
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What is the NIEM Model Package Description?
The NIEM Model Package Description (MPD) Specification defines terminology, identifies required and optionaland , specifies normative rules, , syntax, and provides non-normative guidance to support the creation of an IEPD. As defined in the MPD Specification, an(a subclass of an MPD) contains NIEM-conforming schemas that define one or more recurring data exchanges. Schemas that are considered NIEM-conforming are conformant with the rules and requirements identified in the NIEM Naming and Design Rules (see above).
Sections of the MPD, relevant to IEPD development and packaging include:
- Section 2.9.4, Information Exchange Package Documentation (IEPD)
- Section 2.10, Similarities and Differences of MPD Classes
- Section 3, MPD XML Schema Artifacts
- Section 4, MPD Documentation Artifacts
- Section 6, Directory Organization, Packaging, Other Criteria
- Appendix F, MPD Artifacts
- Appendix G, MPD Lexicon (Nature and Purpose)
- Appendix H, Rule Summary
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What training is available?
NIEM provides comprehensive training for those interested in utilizing NIEM in their organizations. Designed for both technical and non-technical audiences, our curriculum spans all things NIEM, from the basics to advanced technical implementation. Classroom training is scheduled a few months in advance. Online training is free and available anywhere, anytime you need it!
NIEM technical training assumes an intermediate-level of experience, particularly related to XML definitions and object-oriented design. To assist you in building XML foundational skill sets, free online XML training classes are available at http://www.w3schools.com and http://www.w3.org. If you know of any other free XML training online, please email us at information@niem.gov so we can share the information with the NIEM community.
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How do I engage with NIEM?
As a community member of NIEM, your involvement could span one or more . You also don’t need to be aligned to a formal NIEM domain to use NIEM, as NIEM’s core elements are universal and applicable to many or all.
What is a NIEM domain?
NIEM domains are communities of interest, or COIs, that are formally established, with an executive steward, to officially manage and govern a portion of the NIEM data model. Domains are formalized based on business need, not limited in scope to any one organization or agency. For more information, click here.
What is a COI?
A COI is a group of people who share a common concern, set of problems, or interest in a topic. Within the context of NIEM, COIs come together based on a common need to exchange information in order to advance their missions.
COIs can be composed of multiple domains or can be a sub-set of a single domain. For example, a multi-faceted issue, such as human trafficking, involves both law enforcement organizations to handle investigations, and immigration and social service organizations to provide victim assistance. Therefore, the anti-human trafficking community includes stakeholders from the Justice, Human Services, and Immigration domains. Conversely, a broadly scoped domain such as the Maritime domain could contain multiple COIs such as Coastal Defense, Marine Protection, and Fisheries.
Easy ways to join the NIEM community:
An integral part of using NIEM is connecting with other NIEM users. The global NIEM community is full of experienced members who you can leverage to help your organization meet its goals.
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