Understanding JDF (Job Definition Format)
"JDF is a comprehensive XML-based file format and proposed industry standard for end-to-end job ticket specifications combined with a message description standard and message interchange protocol."
If you are a technical junkie, then you should read one of the white papers that populate vendor and technical-association websites. If, however, you simply want to know the basics so you can understand how JDF can benefit your business, then continue reading.
JDF is an XML (eXtensible Markup Language) standard or specification. So to understand JDF, you need to understand XML.
A markup is a tag or a code that identifies information. For example, if you saw the words "Delilah (dog) is dangerous" the parenthesis or "tag" would tell you that Delilah was referring to an animal and not the biblical vixen. It could also tell you that Delilah is a Doberman Pincher and must always be handled a certain way. In print production, tags such as approval and trapping attached to a page would provide instructions for trapping and tell you that the page needs to be approved before final processing. It could even have instructions where or to whom to send for approval. In this way, when the page is ready it can be sent automatically to the client for approval.
"Extensible" means XML tags are unlimited. You can add as many tags as you like. In addition, you can supplement them with other files to further define and extend the instructions. This is why you can apply content to a template for a webpage and for print. Both will look different but the elements of the content will go into their proper place. XML understands the difference between text and graphics and treats them accordingly. But in order for competing systems to "interoperate", they must use the same tags speak a universal language, if you will. This is what JDF does. It provides standard tags so that all systems and MIS functions speak print fluently.
JDF is then written into workflow software, project management systems and other system drivers. Providing a standard requires an independent organisation. That is the job of CIP4 (International Cooperation for the Integration of Processes in Prepress, Press and Postpress). CIP4 was founded in 1995 (as CIP3) as an initiative of graphic arts vendors. Today CIP4 comprises more than 180 members with 20 working groups. Its primary goal is to develop vendor-independent international standards to extend connectivity beyond production to include business processes, client collaboration and job delivery.
To make JDF a truly vendor-neutral data exchange standard it is necessary to work out specific Interoperability Conformance Specification (ICS) and perform Interoperability Testing so that all systems use the same definition format. This, too, is the charter of CIP4 (www.cip4.org). JDF goes beyond XML in that it includes validation schema. This enables and automates processes such as preflighting. It also allows for a selection of a networking protocol and methods of exchange. It automates online transactions and data exchange. All told, JDF is the key technology driver of the evolved workflow the Graphic Enterprise.
JDF in Action
A good way to understand how JDF works is to imagine an intelligent mobile robot that moves that moves information, project components and instructions back and forth to the appropriate systems, departments and remote locations.
JDF - JMF
It is important to note, however, that JDF gets much of its mobility from JMF (Job Messaging Format), a subset of JDF. While JDF describes the project and gives the specific commands to execute the job, JMF provides the means for parallel processes, such as production and administration, to communicate. As its name suggests, it is the JDF messenger. It relays information about the progress of JDF jobs and gives MIS the active ability to query devices about processing status.
JDF and JMF work hand in hand to automate online transactions and data exchange. Think of JDF as the brains of the robot and JMF is its legs. It starts with the client. When a sales person or customer service rep enters specifications for a project, the JDF robot captures that information. When files are received, it understands, not just what needs to be done, but what is required in order to do the job properly. If a font is missing, it will automatically alert the client or designer. When JDF finishes validating the project components and the process is ready to begin, it sends the data to all departments and partners that will participate in the execution and delivery of the project. It also attaches the data to the project files and adds information for how the project needs to be executed. Because this is no ordinary robot, but an intelligent interactive agent, it assists the workflow software in searching out which systems within the organisation are free and assigns the job to the appropriate system.
As the project travels through the workflow, JDF logs all processing data and sends that information back to MIS. That information can be used for cost purposes and to track the status of the job. If a system is hung up for some reason, the robot races back to recognised users and alerts them of a problem.
JDF knows when a job is ready for approval. It takes the pages and transports them through the approval process via email, or the users' preferred delivery system. It can even send a message to a mobile phone. JDF also replicates data. That is, while it is alerting a user about a problem or sending pages for approval, it transmits the same information to MIS (via JMF) for job-logging purposes. The JDF robot has is a secure transport system. It knows exactly who to send data to who has permission to check job status, provide approvals or stop and start processes. Only those people can intervene in the process. Among its duties is to pass instructions along to the press, which would include screening options, process control, ink-key settings, laminating and folding instructions, depending on the presses capabilities which the JDF robot would have made note of and entered into the process.
If the system knows that the job is distributed over two or more print sites, JDF takes all the data that has been entered to date, travels with the files and executes processes automatically at the remote sites. It can take into consideration all the equipment located at the remote location. The JDF robot eliminates the need to re-enter or rework data. The JDF shuttle also sends shipping instructions to all respective distribution companies. Personalisation is no problem for JDF. It knows at which point data must be entered or replaced and provides the appropriate instructions for the RIP and output equipment.
Think of the JDF robot as the ultimate customer service rep. It knows how clients and partners like to receive information. It knows what protocol or type of network they use and delivers information accordingly. JDF Today Not all of the functions described above are ready today. However, many of them are and it will not be long before all of them are written into the software that controls the Graphic Enterprise. All JDF-powered systems have the capacity to enable the Graphic Enterprise. However, the process of building the Graphic Enterprise does not stand on the shoulders of the technology providers alone. Printing companies and partners need to be part of the process. They need to partner with the vendors to carve the path to the future.
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Ing. Rainer Wagner
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