The IEPD life cycle
A best practice life cycle approach for developing IEPDs has evolved through the work of some notable IEPD development projects. Largely spearheaded by the user community, the IEPD life cycle comprises six key steps shown in Figure 1 on Page 118.
The IEPD life cycle focuses on identifying the business requirements and turning those requirements into an XML technical implementation model. In each stage of the life cycle, a defined set of artifacts or documents represents the policies, specifications, data requirements and implementation strategies of an exchange. The artifact set is generated using a set of open source or commercial off-the-shelf (COTS) tools that are readily available to most criminal justice policy setting and information technology departments.
The six steps of the IEPD life cycle are:
- Initialization: Basic business requirements associated with an information exchange are identified. The data to be exchanged, the exchange partners and a general mission statement of the function of the exchange are defined. A basic description of the business strategy, need for the exchange and benefits to be derived are developed. Finally, the initialization stage defines the general implementation strategy to be applied once the IEPD is complete (i.e. SOA, transactional, query, response, service model, etc.)
- Business Process Model: Process use cases for how the exchange information occurs within the business domain and how each will be executed when the exchange is implemented. The use cases define the triggering events; the agencies, departments and roles of exchange participants; the business rules or conditions affecting the exchange; and the data packages or business documents which contain the exchanged information.
- Business Data Model: Data requirements for the exchange based on business terminology and requirements are documented. The general data packages defined in the second step are normalized into business objects (persons, organizations, places and things), and each element that could describe the object is identified, named and defined.
- Standards Transformation: The business data model is converted into an XML standards representation identifying the schema types and properties representing each object and element in the business model. The business model can be converted into different data model standards (e.g., GJXDM and NIEM) without impacting the business requirements of the exchange.
- Schema Package Development: From the mapping developed in the fourth step, technicians create the schema packages to be utilized in the exchange based on the strategic implementation objectives established during initiation.
- Testing and Implementation: Since the goal of an IEPD is to provide documentation for a reusable exchange, the IEPD and its schema set are tested to demonstrate they can successfully meet the business and technical requirements of the exchange. Documenting a description of how the exchange and IEPD was tested and implemented provides users with guidelines for reusing the IEPD within their environments or domains.
The last three stages of the IEPD life cycle convert the business need requirements artifacts into a standard set of technical artifacts or XML schema sets. This process typically involves mapping the business content requirements into the specific XML vocabulary standard such as GJXDM or NIEM. Since the XML schema set mirrors the business requirements for a specific exchange, technicians are assured what they construct actually does reflect the information exchange requirements.