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about 9 years ago

VistA Open Source Compatibility Definition

Please view this document in entirety in PDF format at http://www.ehealth.va.gov/docs/mass/TCMS-Definition_Compatibility_OpenSource_VistA.pdf

This document defines the concept of “Compatibility with Open Source VistA” for the purpose of the Scheduling Package Challenge.

The Open Source Electronic Health Record Agent (OSEHRA) has created an open source environment for VistA, and is hosting the VistA FOIA version as the core of this code base. In this document, this version of VistA is referred to as Open Source VistA.

Strict Definition of Compatibility

In the strictest sense, an external application or a new software component is “compatible with open source VistA” if, when integrated with open source VistA, all the functionalities of VistA continue to operate as they did before the new component was integrated.

This definition is based on the concept of “Do no harm”, that when applied to a software platform, translates to “Do not break any existing functionality”.

In practical terms, after the installation of the contestants’ software, all systems and users that interact with VistA, should continue to operate as they did before, without any alteration.

Given that the set of all possible interactions with open source VistA, is too large to be thoroughly tested and verified, this strict definition of compatibility is mapped to the following operational definition of compatibility.

Operational Definition of Compatibility

In a practical sense, an external application or a new software component is “compatible with open source VistA” if, when integrated with open source VistA, a specific set of VistA functionalities that are objectively testable continue to operate as they did before the new component was integrated.

This condition is verified by OSEHRA utilizing a set of contestant-supplied automated software scripts that are run as “tests” against both the unmodified version of open source VistA, and against the combination of the new component integrated with open source VistA.  The new component will be called “compatible with open source VistA” if the set of tests produces the same results before and after the integration.

For details on the Use Cases that contestants will have to demonstrate via automated scripts, please refer to the document “TCMS – Step 1 Test Cases”

The specific set of tests includes both input and output activities that can be performed via the roll-and-scroll interface, the CPRS (Computerized Patient Record System) interface and RPC (Remote Procedure Call) calls.