Following a standard protocol provides you with an advantage of connecting to any system that supports this particular part of the standard, both now and in the future. For example, Internet Explorer or Netscape can connect to any existing and future web server using HTTP and HTML standard protocols.
Adhering to a standard protocol is called "open system architecture". Anybody can interface with an open system using appropriate protocols, independent of its vendor. When using HL7, the interface allows for numerous systems to be added to a single HL7 feed. New systems can be added without having to modify the original source system as demonstrated in the following diagram:
Now consider the proprietary system model:
"Closed" and "Proprietary" are used interchangeably throughout this section to mean that characteristics of the system are hidden by the vendor from the public domain. Although the closed-system model is easier to design and initially costs less to implement, closed systems have greater reliability on single vendors and more reliance on specific applications and technologies.
Although the worldwide trend is to follow an open-system architecture, there are still tradeoffs in following a standard protocol when developing interfaces. For instance, a greater initial investment is required. Time and money must be spent to understand the standard and create the infrastructure required to support the standard, such as a parsing framework and networking code.
However, the benefits are abundant. For example, it will be easier to answer user requirements because HL7 is considered the standard for exchanging data between healthcare systems. In addition, because HL7 is the standard, it will be easier to create a system that can interface with an open system now and in the future.