The Department of Veterans Affairs (VA) is beginning the process of implementing the Cerner electronic health record (EHR) system across all care sites with a target of 2028 for completion. Currently, Cerner is settling into a sea of VA systems that their Cerner medical records platform must interact and interoperate with. An emerging impediment to accomplishing this is the challenge of connecting their development and test environments to VA or getting documentation confirmed with VA. What Cerner and others in this same situation can use as a remedy for absent system connections and formal documentation is the creation and incorporation of test harnesses.

maybe test harness graphic

test harness is a combination of software, system test drivers, and other tools that are required to execute tests on any given system. It provides stubs and drivers: programs that simulate the behaviors of and interact with software during a trial. Integration testing involves group testing between units to ensure they interact as expected. For the implementation of the Cerner EHR, this type of testing is needed to ensure Cerner can connect to all the right VA systems and will exchange information as expected once it goes live.

A struggle can emerge when any organization is attempting to get their systems connected to another agency’s enterprise network, much less as part of establishing a major EHR implementation for an enterprise-wide transition. From potentially conflicting policies and procedures across organizations to multiple layers of teams to navigate within organizations, it can be difficult getting access and documentation for all the systems and components needed for proper testing. Test harnesses are a useful solution for this problem because they can simulate missing systems and components such as the ones Cerner will need to interface with for the VA EHR transition. For the purposes of integration testing, this means Cerner can use test harnesses to simulate VA systems where they are unable to obtain necessary access or documentation.

In cases where there is no system documentation, it may seem tricky getting test harnesses set up to properly simulate those systems. After all, for the test harness to be effective for integration testing, it needs to provide a good simulation of how the system will behave when connected. A solution is to log or record data transmissions from the target system to develop a model for how it will interact, such as capturing how medical records may be transmitted from VA systems to DoD for Cerner. From there, this model can be used to create a test harness capable of serving as an effective simulation of the target system for integration testing.

“A struggle can emerge when any organization is attempting to get their systems connected to another agency’s enterprise network…”

I have personal experience with using test harnesses to successfully assist in furthering Cerner’s interoperability with VA systems. I’ve recorded application program interface (API) calls using SOAP UI or RESTful, an API that uses HTTP to get, put, post, and delete data. In the past, I have also recorded messages from VA. The recordings included HL7 messages, used to transfer data and information about particular events (ex: patient admission, discharge) between different healthcare systems. I then used these recordings to make mock services and clients for Cerner to continue integration testing for its use at VA.

With the implementation of the Cerner EHR underway, ensuring the system’s interoperability with the VA is crucial to the success of this transition. Test harnesses can help teams overcome the challenges of missing access or documentation by enabling effective integration testing and validating system interoperability. For Cerner, this would help ensure they are ready to connect to required VA systems as their EHR goes live across the nation, providing a seamless transition in support of our Veterans.