Silos: good for corn, bad for data
Most of you have heard of the tower of Babel, the biblical story where upon building a tall tower designed to reach to heaven, humankind was scattered across the earth, and deprived of a common unified language, such that they could no longer communicate with that unified language.
In manufacturing this problem is still evident even within a single factory, and todays towers are known as data silos. A data silo is a place where measurement data goes in, and nothing comes out. Money is spent on measuring devices, and hours are wasted gathering process data that is never really evaluated or used to make informed decisions that would improve a process.
This is not an article about SPC; this article is about recent developments and new emerging technology that can help simplify data collection and management.
The automotive industry has embraced statistical process control (SPC) as best practice for monitoring manufacturing processes, as using the measurement data to reduce variability in manufacturing processes, so we have cars with consistent quality. All high-volume parts suppliers are required to apply SPC to their processes and provide data to the customer in most cases as well. SPC – the brilliant legacy of Ed Deming only a mother could love (and “stat-heads” and smart manufacturers). The methodology of SPC has been in practice for over three decades in the US automotive industry, yet even still the application of it is very uneven. Every week I walk through plants, and see stand-alone gage benches where the gages are not hooked up to send data anywhere, and in many cases operators are still hand-charting measurement data for management. Yuck – even though they are getting paid to do it, those operators can’t be loving hand-charting data. Even worse, hand-charting is guaranteed to produce mistakes.
Many machine operators would rather check a needle position on a dial indicator rather than look at a row of numbers. Old reliable- the dial indicator. True story – not very long ago a tier 1 automotive parts supplier had an $800,000.00 dial indicator mistake. A machining problem caused the part to be so oversized that the needle rotated nearly a 360, such that the part feature being measured appeared to be under-sized. So, they made what they thought was the appropriate correction. This was one of those stand-alone gages, nobody was tracking the hand-charted data, and they made and shipped very many bad parts before the mistake was discovered.
Bringing the conversation back to the CMM, and the metrologist… do your CMM inspection routines export data into an SPC program? If so, does your CMM use the same SPC software as the rest of the plant? Finally – do all the gages on the shop floor deliver critical measurement data to the same universal process control software that is plant wide? If not, then your plant is suffering from a modern-day version of the tower of Babel syndrome. The simplest solution is to go with a universal data management software that talks to all most all measuring machines and gages.
There may be a variety of software and solutions that overcome this problem, here are a couple of popular products we can use for reference. QC-Calc from Prolink is the most common and popular software on the market for providing real-time data charting for CMM and vision systems. It’s easy to implement, and the cost is very reasonable. I mention this product specifically, as it is nearly universal for pretty much any brand of CMM or video measuring system, and if your brand is not currently integrated, they will typically get it done is a week or less. Most folks prefer fast and easy.
It gets better – these guys have developed additional modules that talk to a wide variety of digital indicators and probes, and pump the data in into QC-Calc Real Time, the same module that many of you have running on your CMM or vision system. They even communicate with laser sensors and PLCs. Taking it upstream they have enterprise wide modules that can let you look at the data coming off all the gage cells on the floor, and even use your smart phone to look at run charts when you are remote from the plant! Sure seems like it would simplify life if all the measuring machines and devices were all communicating in the same language.
Going back to that gage on the floor where the measurement data is stuck in a silo. The problem can be caused by a variety of reasons – dial indicators don’t talk, purchasing bought digital indicators with no output ports, even a sophisticated gage with a bunch of LVDT pencil probes may have a proprietary operating system that doesn’t communicate with the plant-wide SPC program sitting up in an office somewhere. How do you start to fix that?
At the lower end of the spectrum, start using sensors that have data export functions. Even digital hand tools that need to be portable come with Blue-Tooth, or more universally – have a Micro-Ridge wireless transmitter plugged into the output port, which gives the same universal signal (regardless of tool brand) to your universal process control software (like Prolink).
Providing a gage station with a computer and display is becoming simpler and much less expensive. There are fan-less mini computers available now with digital hard drives that are only a few inches in size. They come with Windows 7 or 10 operating systems, and can cost less than the digital indicator or probe. They are designed to run reliably on the shop floor.
At the high precision end, many of those fancy gages have LVDT pencil probes that are integrated into some proprietary computer and software. It doesn’t have to be that way.
Magnescale, Marposs, and Mahr now have digital gauges and indicators with a USB interface. They have many different models. The Magnescale probes resolution down to 0.0001mm (0.1µm) for tight tolerance applications, and replace analog LVDT technology with true digital technology. These products are all available from AA Jansson.
These will plug right into that new mini-computer, and include free software that makes some basic calculations, displays values, and/or exports a CSV file that can feed into QC-Calc or Excel. Some of these mini computers even support dual monitors if you want to separate the basic readings and the QC-Calc process control charts. The software can also run in the background with the QC-Calc upfront.
The point of this discussion is that new technology is emerging that facilitates fully integrated gages and measuring machines plant wide. All the measuring devices can communicate into a universal process control software with real-time feedback for the operators, and higher-level analysis for the statistical gurus. Even remote monitoring of real-time control charts with smart phones for every measuring device in operation in the plant is available now. While some of this may sound complicated, it’s easier and far less expensive to implement than ever. Going universal and eliminating measured data silos will provide companies with big savings, and productivity gains by simplifying process control.
written by: Dan Smith