Metrology for lean manufacturing: EM Sleuth's enterprise metrology self-assessment guide (the short form).
Enterprise metrology, like lean manufacturing, saves manufacturers a great deal of money. However, those are small savings compared with what happens when enterprise metrology systems make it possible for lean manufacturing practitioners to produce systemic cost reductions.
How far in implementing enterprise metrology is your manufacturing operation? To what extent are the tools giving your lean manufacturing team the ability to sleuth out waste and inefficiencies?
To begin, let's evaluate your progress in the six areas that define enterprise metrology:
* Early integration of measurement with CAD;
* Common look, feel, and functionality of measurement system control and operation;
* Streamlined, flexible part programming tools;
* Open measurement database accessible by a wide range of analytical tools;
* Flexible reporting capabilities;
* Enterprise-wide dimensional information publishing.
Up front with CAD
The manufacturing process starts with design. Enterprise metrology closes the loop between inspection and design by providing feedback on how well manufacturing is meeting the implicit and explicit requirements built into the CAD model both at its creation and through its lifecycle.
The best practice is to make design intent explicit at the very beginning by encoding GD&T (geometric dimensioning and tolerancing) data electronically into the CAD model. In some cases, this happens when engineers develop measurement programs directly on the CAD system, using either proprietary tools or software based on standards such as DMIS. Recently, popular CAD software packages (e.g., Solid Works and Unigraphics) have begun providing tools for embedding GD&T data into the CAD model. Consequently, designers now have a highly flexible method for making their intent an integral part of their models in the form of inspection plans.
CAD-based programs such as Wilcox Associates' IP Planner use this capability to create "electronic blueprints" that accompany the model to the CMM. There a second program, IP Measure, uses it to automate most of the job of part programming. This eliminates most data entry errors and reduces programming labor by as much as 80 percent.
Metronor's AIMS uses an alternate approach. A special data collection module accompanies the CAD model to the measurement system. This module causes the measurement system to capture sets of points on the part being inspected and writes them into a database. This database is then sent back to the CAD system where a built-in metrology component accesses the data and uses it to analyze and evaluate the part.
These examples represent two very different approaches to integrating measurement and analysis with CAD. The approach you use depends largely on the size and complexity of your manufacturing operation along with how much flexibility specific departments need to solve their unique problems. Two questions you should ask to assess your own capabilities and needs include:
* Are you using CAD files to develop inspection programs and programs for CMMs and other measurement devices?
* Have you found a way to make GD&T information CAD-resident and transfer that to the measurement device?
Look, feel, function
As much as possible, measurement systems in the lab and on the shop floor should have software with a common look, feel, and functionality. After all, people can accomplish much more when they are intimately familiar with their tools.
Using Windows-based soft-solving these problems. Having a common metrology software system does the rest. Such a comprehensive solution includes software usable on multiple brands and types of equipment, including CMMs, vision machines, probe-capable NC machines, and the like. Some are even capable of sharing measurement programs among dissimilar types of equipment.
Some important questions to ask:
* Is common software with a consistent look, feel, and functionality a consideration when you evaluate measurement equipment?
* Do you use a single control and operating software package on all or most of your CMMs?
We take for granted the capabilities of high-speed DCC measurement systems that can perform, in hours or minutes, complex inspections that might have required days or even weeks only a decade ago. Now all the labor is in programming, which can be especially costly and nerve-wracking in the early stages of manufacturing process development--when everything is needed yesterday.
Today, it is possible to reduce this labor and cost substantially. Options range from simplified point-and-click programming using a CAD model as a template to automated programming that takes design intent embedded in the CAD model and translates it into a part program that is almost ready to run. Sharing these programs among different types of inspection equipment offers even greater opportunities for savings.
Here are a couple critical questions to start with:
* To what extent are you capable of programming offline so that valuable measurement systems can continue operating?
* To what degree do you use CAD models for automated point-and-click programming?
Open DB and analysis tools
It is vitally important that all measurement data, regardless of the source, go to a common database open to best-in-class analytical tools. Data are stored in a consistent format and are easily accessible by all sorts of applications for multiple purposes. The result is a powerful competitive advantage.
Only you can decide which analytical tools are appropriate to your lean systems. They might include very specialized commercial or homegrown packages for gear, blade form, or mold shrinkage analysis. Or possibly just a good quality SPC package may be enough to meet your needs.
Some questions you need to ask:
* Do you have a common metrology information database that is open to a wide range of best-in-class analytical tools?
* Is your metrology information database robust enough to handle large volumes of data generated by all of your measurement devices, including those, such as vision and laser equipment, capable of generating huge volumes of data?
Enterprise Metrology systems must include reporting capabilities that get information to those who need it in an appropriate and unambiguous format.
Good reports filter out volumes of analytical noise. They require little if any explanation. Enterprise metrology reporting capabilities should include standard statistical charts and graphs, basic tabular and graphical reports, and customizable 2-D and 3-D CAD-based reporting modules.
Here are some things you need to ask yourself.
* Do you have the capability to create a wide range of graphical reports appropriate to the data analyses?
* Do you have the capability to automatically annotate CAD drawings with unambiguous dimensional or statistical information?
Generating incisive reports is of little value if they are not readily available to anyone who could make use of the information. A few years ago, just setting up the infrastructure for this would have been a problem for most companies. Today, the tools for enterprise metrology publishing--including the Internet, extranets, VPNs (virtual private networks), and good, old hardwired LANs are accessible to organizations of all type and sizes.
Infrastructure is one requirement for effective enterprise metrology communications. The second is to fully automate metrology information publishing. While not quite there yet, these automated publishing applications are beginning to emerge. Soon, Web-based publishing software will become a key component of any lean manufacturing program.
Important questions include:
* To what extent is your existing communications infrastructure capable of publishing metrology information throughout the manufacturing enterprise?
* Who can keep you apprised of new publishing and other enterprise metrology tools as they become available? (Hint: the EM Sleuth column in Tooling & Production and www.pcdmis-ems.com are both good candidates for the list.)
Now Get The Long Form
Now that you have breezed through this article and answered our short-form questions, you may see the need for a more in-depth assessment of where you stand with enterprise metrology. For this, Tooling & Production will be posting an Enterprise Metrology Assessment Spreadsheet, which contains a more comprehensive set of questions and assessment scorecard.
Enterprise metrology is and will remain a work in progress and so is our scorecard. We will be expanding and improving on it based on your comments and questions. Please address them to the EM Sleuth at www.pcdmis-ems.com.
EM Sleuth is sponsored by Wilcox Associates Inc, (www.pcdmis-ems.com), part of the Hexagon Metrology Group and makers of PC-DMIS measurement software. Contributors to this article include: Ken Woodbine, vice president, Wilcox Associates, email@example.com; Steve Logee, director of business development, Wilcox Associates, firstname.lastname@example.org; Rob Fabiano, Sleuth illustrator, email@example.com and Joel Cassola, writer, jocas@cox.