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What is JDF
JDF is an acronym for Job Definition Format. JDF is an open and expandable standard, which encompasses the entire workflow from the order, through prepress, printing, and post-print handling, to delivery and billing. The goal is to achieve faster, simpler, and more cost effective production.
The driving force behind JDF is the organization CIP4, which is responsible for developing the standard and for making available information about this standard. The organization has managed the standard since 2000 when the standard’s initiators, Adobe, Agfa, Heidelberg, and Man Roland, introduced JDF in its more definitive form.
At first glance, what might be confusing about JDF is that the concept refers to two different things. It is a designation partly for the actual standard and partly for the file, the electronic worksheet, which is sent through the workflow.
To clarify, one can simply say that the standard JDF is comprehensive, documented knowledge when considering the idea as a whole. The actual standard is made up of two parts, JDF (Job Definition Format) and JMF (Job Messaging Format). The file JDF contains the overall structure describing which processes and resources are part of a specific order. For example, impositioning data, color settings, order information, delivery information, and detailed product information can be saved in the file. The file is easy to recognize as it has the extension .jdf.
JMF is a command/control language, which the standard JDF makes available as an interface between the management system and the production equipment. The management system is sometimes called MIS (Management Information System). MIS’s task is to store and manage information from every individual process. With JMF’s help, the management system can, for example, send a message to the production equipment to start or stop a job. Alternatively, it can be used to report where in the workflow a job is located or how many plates have been produced. JMF messages are also sent as files and are easy to recognize as they have the extension .jmf.
A Growing Standard
As JDF is a growing standard within the graphics industry, it is compatible with equipment from many different suppliers. The standard is intended to be both platform and supplier independent. The standard is quite extensive and it is unreasonable to expect every software supplier to support the whole standard. One has therefore decided to divide it into a number of smaller parts, which each handle a different part of the flow. These parts are called ICS (Interoperability Conformance Specification). For example, there is an ICS that defines the interface between the management system and the prepress. Another defines the interface between the management system and the conventional press. To ensure that everything will work, the receiver of the file must of course support the same ICS as the sender. Another thing that can be worth knowing is that the JDF specification has been released in several different versions. The communicating parts must all support the same version to function optimally. The latest version (1.3) was released in the fall of 2005.
JDF is based on the Meta language XML (Extensible Markup Language), which is a standard intended to tie together systems that previously have been out of each other’s reach. The idea is that with help from JDF, one will be able to automate the workflow regardless if the connected equipment is from the same manufacturer or not. To achieve platform independence, a JDF specified schedule that establishes how the XML file will be structured to be an approved JDF file, which is negotiable in all types of systems that support the standard, is also needed.
The JDF standard is, as stated above, intended to be supplier independent, which can first be achieved when all equipment on the market has support for JDF. Fortunately, most of the larger suppliers have already begun this effort and the vast majority can today offer some form of support for the standard. Furthermore, many of the larger suppliers can arrange for older equipment to be made compatible with the standard. However, the support between different suppliers could, in many cases, be better.
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