Jeff's MCAD Blogging
Jeffrey Rowe has almost 40 years of experience in all aspects of industrial design, mechanical engineering, and manufacturing. On the publishing side, he has written well over 1,000 articles for CAD, CAM, CAE, and other technical publications, as well as consulting in many capacities in the design … More »
QIF: A Realistic Framework For The Future Of Manufacturing
September 8th, 2016 by Jeff Rowe
Interoperability, collaboration, inspection, quality, standards, proprietary data, neutrality, competition, and innovation – these are words and realities that all manufacturers deal with daily. Over the years there have been myriad attempts to bring this stuff together, all while protecting IP. However, as we know, while the attempts to make this happen have often been valiant, too often they have fallen well short, or worse, failed altogether.
That failure may be on its way to being a thing of the past with the advent of the Quality Information Framework (QIF), an ANSI standard that supports digital thread concepts in engineering applications ranging from product design through manufacturing. Based on the XML standard, it contains a Library of XML Schema ensuring both data integrity and data interoperability in Model Based Enterprise (MBE) implementations.
QIF supports design, metrology, manufacturing, and is critical to the Industrial Revolution 4.0. Because it is XML based, QIF can be relatively easily integrated with Internet applications, and unlike other existing standards, there is no real barrier standing in the way for industry adopting QIF. It also effectively supports newer technologies, including additive manufacturing and the Internet of Things (IoT).
With QIF, all discrete manufacturers now have a standard platform that ensures quality while minimizing costs and making processes more transparent.
All information models for transporting quality data are derived from common model libraries so that common information modeling components can be reused throughout the entire quality measurement process. As a consequence, the entire process is inherently interoperable.
ANSI QIF is made up of the following eight parts:
Part 1: QIF Overview – Description of the general content and structure of the entire QIF information model, including the highest level data structures.
Part 2: QIF Library – Core QIF data structures used throughout different QIF application areas.
Part 3: QIF Model-Based Definition (MBD) – Defines a digital data format to convey part geometry (typically called the “CAD” model) and information to be consumed by downstream manufacturing quality processes, such as PMI.
Part 4: QIF Plans – Defines the digital format to convey measurement plans, which could include a set of features and characteristics to be measured, resources to be used, measurement procedure to be used, etc.
Part 5: QIF Resources – Digital definition of dimensional measurement resources, sufficient for use in generating a high level measurement plan for product certification, acceptance, or any other common application of dimensional measurement data.
Part 6: QIF Rules – Defines for format for specifying measurement rules, which are also sometimes referred to as measurement templates or measurement macros.
Part 7: QIF Results – Defines the format for specifying results of quality operations.
Part 8: QIF Statistics – Used to define statistical analysis of a set of results (for example, individuals, averages, standard deviations, max, min, etc.)
The diagram below shows the six QIF application area information models, Model-Based Design (MBD) which is equivalent to QIFProduct, Plans, Resources, Rules, Results, and Statistics. The “QIF Execution” model is, in the current version of QIF, a placeholder for future standardization. The order of generation of QIF data generally proceeds clockwise around the diagram, beginning with QIF MBD and ending with QIF Statistics. Users of the QIF information model are not required to implement the entire model for it to succeed. In other words, any of the six application models can be used individually for exchanging quality data between software systems.
How QIF Works
The flow of QIF data starts with generation of CAD + PMI data exported as QIF Model Based Design (MBD) application data. Quality planning systems import the MBD and generate Plans (“whats”), then import Resources and Rules information and export Plans (“whats’ and “hows”). Programming systems import Plans to generate Dimensional Measurement Equipment (DME) specific programs, or general instructions to guide inspection. Dimensional measurement equipment executes programs and evaluates characteristics of a single manufactured part or assembly and exports the measurements as Results. Analysis systems, typically performing statistical process control, import single parts Results and generate analysis of multiple part batches as QIF Statistics data.
QIF is intended to handle both lossless feed-forward information translation, and cater to the ability to provide feedback integration to the product lifecycle in a unified and universal XML format. Currently, the translation from a CAD model based definition into the QIF format has been approached, and commercial products are available and standard processes being developed. One goal of QIF is to satisfy the input specification requirements of GD&T. Another goal of QIF is to satisfy the requirements derived from output results of quality assessment standards.
From the beginning, QIF has been fostered by the Dimensional Metrology Standards Consortium (DMSC) based on the realization of the need for a “common communication language,” because every CAD system produces its own output measurement language, and every coordinate measuring machine (CMM) had its own internal language that it accepts for processing. Like older machining languages, translators and “post-processors” have become rampant (as in, a problem not quite yet solved). Every CAD system has to have a different output for every coordinate machine in the factory. A common language has been badly needed for some time. Thus, the need and advent for QIF that hopes to resolve these age-old problems of interoperability.
DMSC’s mission is to identify urgently needed standards in the field of dimensional metrology, and to promote, foster, and encourage the development and interoperability of these standards, along with related and supporting standards that will benefit the industry as a whole. QIF is one of the results of these standards that the consortium has the responsibility to continue development, maintain and support, as well as to coordinate with other related standards efforts.
While a bit slow in getting started, QIF is quickly becoming one of the true universal manufacturing standards that is very likely to stick and proliferate. Many companies have made a lot of money in a lot of ways through non-standard, proprietary data, but that will change in a big way through the acceptance and adoption of QIF. With QIF there is still plenty of potential for a lot of money to be made. This time, however, the card deck will be dealt to everyone equally instead of being stacked for the benefit of relatively few.
Admittedly, standards, by their nature are dry, but QIF and its implications and benefits are so broad, I’m hoping most manufacturers will take notice and adopt it.
We believe that QIF is such a big deal for manufacturing moving forward that we will devote significant coverage as developments unfold in the coming months and beyond. Because there is so much to cover, I’ll dive into several of the above parts of QIF and how adoption will improve the lives of those who take it on. If you have an opposing view of QIF, I’d like to hear that, as well.
Editor’s Note: We’ll be in Chicago next week for manufacturing’s greatest show on earth – IMTS. Hanging out for the week with about 100,000 other attendees, we’ll be conducting video interviews and checking the design, engineering, and manufacturing innovations that will be on display, as well as an exclusive meeting with DMSC. If there is anything special we should know about at IMTS, make sure you get a hold of me at 719.221.1867 or email@example.com. Hope to see you there!