JDF BASICS -- It's Just the Ticket
The design of JMF potentially allows for direct communication between pieces of equipment that support it. However, the specification advises that—in almost all cases—a print shop will want to set up all of its production equipment to communicate with a MIS (Management Information System). "It is the MIS system that controls the scheduling, execution and management of work in progress. The role of this system is described within this standard, but it isn't highly defined," the documentation reads.
Throwing a Curve
Some of the smallest parts of the specification raise the most concern about potential barriers to its successful adoption. The "extensibility" of JDF, for example, is seen as likely being the most contentious issue, but also necessary to avoid limiting its potential and applicability. It allows for system developers and users to add their own XML elements, attributes and enumerations to a JDF application while still being in compliance.
The specification states that "CIP4 acknowledges it can't define everything, nor should it prevent innovation by codifying everything in a static manner." It does offer a strong cautionary note, however.
"If they use extensions to JDF, your technology providers should be able to provide you with a fully validated JDF schema and documentation that includes the use of their extensions. Extensions that are not documented, or that may not be disclosed to third parties for integration purposes, should be viewed skeptically," it advises.
While on the subject of customization, U.S. printers are likely to be interested in the short paragraph on units. Reflecting the European bias in its development, JDF specifies metric units of measurement be used as the default for most values. "That means you can't use alternate units instead of the defined default units. Overriding the default units defined in this table is non-standard and may lead to undefined behavior," the documentation warns.