Message Maker Test ToolHL7 V2 Testing Toolkit
Rob Snelick (

Overview: The Health Level Seven (HL7) standard is a specification for moving clinical and administrative information between healthcare applications. This ability to share relevant information among diverse healthcare systems and provide consistent data across applications helps improve the quality of care as well as improved patient safety and a reduction in the cost of healthcare. The HL7 standard is used by 90% of the hospitals in the U.S. Its adoption in other care settings such as outpatient, long-term care, and telemedicine is necessary to ensure the benefits of widespread electronic communication. However the cost-restrictive nature of managing an HL7 system to achieve interoperability is a concern for widespread adoption in these other settings.

Industry Need Addressed: When originally developed, HL7 was designed to accommodate the many diverse processes that exist in the healthcare industry. This universal design was necessary to gain broad industry support. However, this resulted in a standard that could not be sufficiently constrained to provide a single and consistent interpretation--prohibiting plug and play installations. As a consequence, systems are difficult to implement and debug resulting in undue costs. To help alleviate this shortcoming the concept of message profiles were introduced. A message profile is a proper subset of the HL7 messaging standard that constricts the definition of a message in a manner that specifically states the optional constructs and processing rules of a message. However, if the profile rules are not followed then interoperability problems will still persist. Conformance testing is essential. NIST is developing testing tools to ensure that message profiles are applied as intended to fulfill the promise of interoperable healthcare systems.

NIST/ITL Approach: The introduction of message profiles to the HL7 standard provides a path to conformance and interoperability testing. NIST is building a tool kit that supports the testing of HL7 message interfaces based on the concept of message profiles. The foundation of the tool kit is a set of Java APIs that supports testing activities such as automated message generation and message validation. The APIs can be used to build tools, web services, or they can be incorporated into 3rd party applications and testing environments. Using the APIs, NIST has developed Message Maker, a tool that creates a suite of test message instances for any given profile. NIST is also developing a testing framework and a message validation tool to administer and analyze the results of the tests. Future plans include tools for profile validation and an HL7 data repository. Delivery of the tools will be standalone applications, web services, and web applications.

Impact: There is strong consensus that standards-based messaging, using the HL7 standards, is key for the US to reap the benefits of and electronic healthcare infrastructure. However achieving true interoperability, by implementing HL7 within all of the healthcare sectors (e.g., outpatient, ambulatory, and long-term care) may prove cost prohibitive. Having a strong set of conformance tests and tools, as well as dynamically generated test messages tailored to interoperability will reduce the cost of achieving interoperability.