HL7’ message structure is a computer syntax with fields separated by delimiters which are not user friendly. Because HL7 standard is, by design, flexible and can adapt to all possible workflows, data exchanges between systems implementingthe standard are not 100% compatible. Data exchanged varies for each system or each implementation of the same system.
In addition to how vendors interpret the standard, you may/will find specific customised implementation events, Z-segments, fields, data types or code sets. There is no plug & play method when it comes time to integrate systems using HL7; you need an easy way to define and describe how the data will be exchanged.
Conformance enables you to build, document and understand each system’s HL7 specifications, translate it into conformance profiles and define exactly what actions are required to integrate systems.