‘Attack’ Your Cal Lab Problems
Manufacturers often have a way of throwing process improvement programs at problems. Many, if not most, are abandoned because a lack of interest translates into a lack of results.
The key, of course, is boosting interest, of exciting employees and management, and turning that excitement into positive actions.
Sikorsky Aircraft (Stratford, CT) has found a way to boost interest. It has found a way to empower its employees, and not just with lip service. In one department, the calibration lab, more than 49 process changes have been made in a two-year period, reducing the backlog of instruments from 830 to 295 and the number of days in queue from 18 to 2.5. The calibration lab also reduced costs by more than $60,000 annually.
These changes are not just in new equipment and tools. Most changes are small, most are inexpensive, and most save time and free up personnel. One idea cost only 99 cents to implement. But combined, these ideas have helped a department improve its processes dramatically.
Considering the workload, any help would be appreciated. Sikorsky’s calibration laboratory calibrates an estimated 40,000 gages a year. And, while there are tens of thousands of gages that need to be tuned up, there are only seven people charged with doing the tuning: Quality system manager Chris Papachristos, lead man Michael Hinton and lab technicians Laura Razowski, Dominick Celello, Steve Angelucci, David Warzel and Kathy Tvardzik.
This group used a new process-improvement system that trickled down from Sikorsky’s corporate parent.
History of innovationSikorsky Aircraft Corp. is about 90 miles from Hartford, CT. The facility is a sprawling complex that sits at the first exit that travelers see after crossing over the Naugutuck River on the Sikorsky Bridge.
The bridge and the company are named after Igor Sikorsky, a pioneer in helicopter development. As a child in Kiev, Russia, Sikorsky studied Leonardo da Vinci’s drawings of helicopters and in 1901, at the age of 12, built a rubber-band model of a helicopter. A later version rose a few feet in the air. Eight years later, Sikorsky used a three-cylinder, 25-horsepower motorcycle engine and built a helicopter with coaxial twin-bladed rotors. In 1923, five years after the Bolshevik Revolution drove him to the U.S., Sikorsky built a twin-engine passenger plane and founded the Sikorsky Aero Engineering Corp.
In 1929, the company was bought by United Aircraft Corp., now the United Technologies Corp. (UTC, Hartford, CT). Today, Sikorsky is one of the world leaders in the design, manufacture and service of advanced helicopters for commercial, industrial and military uses.
All five branches of the U.S. military use Sikorsky helicopters, including the U.S. Army’s Blackhawk and the Navy’s Seahawk. The presidential helicopters are made by Sikorsky Aircraft. Commercial companies from more than 40 countries fly Sikorsky products.
In 1993, Sikorsky’s corporate parent, United Technologies, began to implement a new process-improvement program that 10 years later would be used in all of its divisions. The program is called Achieving Competitive Excellence, or ACE. ACE, developed by Yuzuru Ito, a Quality advisor, is a common set of process-improvement tools that, according to its mission statement, is meant to “delight” its customers and “satisfy increased workloads more efficiently.”
Beyond the statistics, the program’s goal is to empower employees and give them the incentives to spot inefficiencies, ask why they are inefficient and develop solutions to remedy the problems. The program calls for small groups of employees who are trained to implement standard processes to work together to develop the solutions. Workers, including all of the members of Sikorsky’s calibration team, attend training at the Ito University, a training session run at UTC.
The system works by identifying that there is a problem, determining the cause of the problem and figuring out how to solve the problem. It integrates Total Productive Maintenance, Set-up Reduction and a focus area called “5S” that stands for sort, straighten, shine, standardize and sustain. The program also integrates Quality control process charts such as Pareto charts, root cause analysis, market feedback analysis and mistake proofing, which calls on workers to use wisdom and ingenuity to develop ways to reduce defects and improve processes.
Chris Papachristos, Quality manager in charge of the Sikorsky calibration lab, has used Six Sigma at past jobs and says that this program is above and beyond that improvement program.
“It allows managers to provide the resources and gives the workers the chance to brainstorm and improve how they do their jobs,” Papachristos says. “The process changes are done in most cases in a group effort. We have learned to share views from everyone so we can come up with the best improvement together.”
Carl Lucas, Quality systems manager/product integrity for Sikorsky, says that the calibration laboratory technicians have developed ideas and gotten excited about their jobs. He says this is reflected in such things as low absenteeism rates.
“The program allowed us to get employees involved in the process—to own it,” says Lucas. “Who knows the problems and how to fix them better than the people working in the lab? It has taken hold in the met lab. This is a proud group that is chock full of ideas.”
LogisticsSome actions taken to fix these problems were purely logistical, and almost tactical in nature. Getting the tools scheduled for calibration out of the workers’ toolbox or shirt pocket and into the cal lab and back was one area that needed to be addressed. Some solutions included an e-mail system that alerts users to due dates for calibration, centralized tool collection bins, a bar code scanning system and a small, red, battery-powered light that was bought at a local hardware store for less than a buck. The light is “Velcroed” to the outside of the calibration lab door. It alerts lift truck drivers, who are making regularly scheduled drop-offs and pickups, that tools are ready to be picked up and distributed to the various Sikorsky facilities. “They used to have to get off the lift trucks and find somebody and ask if we had anything. If we weren’t around, they would have to come back,” says Mike Hinton. “With this light, they know a shipment is ready to go.”
One reason a technician might not have been available is that part of each technician’s day was spent tracking down tools scheduled for calibration. Strategically placed tool collection bins solved this problem. “Used to be,” Hinton says, “we’d send seven people out to the whole company and they would all be gone for one or two hours. Now, with the drop-off locations, one person goes out, and in less than an hour picks up all the tools.”
Workers using tools that need calibrating are notified by e-mail, and if a tool doesn’t turn up in the collection bin, then additional e-mails are sent. “If a gage goes overdue, it stays on our list,” says Lab Tech David Warzel. “If it stays on the list for too many days, another e-mail goes out to the boss.”
These are just a couple of examples of simple ideas that saved time and freed-up personnel. Not all the process changes occurred so quickly, however.
Adding bar codes to each tool in the Sikorsky arsenal took a little more commitment and a lot more time. The bar code scanner was implemented to log in the tools as they came into the calibration laboratory, and it replaced having to keystroke the tool's serial numbers into the computer system. “If a wrong number was entered it would alert us,” says Hinton. “But there were times when a wrong, but valid, number was keyed in, and that caused problems.” A valid, but wrong number inputted into the computer system would be caught at the end of the day by technicians going through a daily aging report, but fixing the problem required them into reenter the system and manually change the serial number.
With more than 40,000 gages in use by Sikorsky workers, Hinton had to place bar codes on all the equipment that came through the door. Even after two years of diligently assigning bar codes, and applying the bar code labels to the tools, the system isn’t fully implemented. Bar code labels need to be replaced because chemicals, dust, heat and humidity, can make them peel off. Even today, every batch or two contains a tool that needs its label reattached.
Despite the time it took to implement, Hinton says tools now get into the hands of the technicians faster than they ever have, which means the tools get returned to the workers faster. In addition, the bar codes provide a lot more information than ever before, including the tool type, its serial number and its calibration history.
Cutting calibration timesMicrometers are the largest-volume tools on the shopfloor, with more than 20,000 tools in use. Each micrometer is calibrated on a 48-week cycle unless the calibration process shows trends that demand the cycle be shortened.
David Warzel is in charge of checking depth, outside diameter, inside diameter, and special micrometers. Each type of micrometer requires specific standards for calibration. Changing over from one standard to the next added a great deal of time to the calibration process because each standard had to soak to the ambient temperature of the room.
One process change looked at ways to speed up depth micrometer calibration. Previously, the depth micrometer was checked using individual gage blocks that were stacked on a surface plate or calibrated parallel bars. Taken from storage, the standards needed to soak to room temperature, and this took up to 1-1/2 hours.
The calibration technicians, working as a team, first analyzed the problem this way: The calibration process took too long because individual gage blocks were used as standards. It asked, “Why was calibration done this way?” and discovered that it was done this way because it had always been done this way—it was the method required by the lab’s work instructions.
And, at the time, the team didn’t know that an alternate method was available; especially because most standard depth micrometer calibration gages did not reach the 12-inch size the lab needed.
The solution, made after researching available products on the market, was a new, custom-made tool called a setting master. The setting master, which is certified calibrated, is “preassembled” in the sense that there are no individual standards. A stand contains the standards in steps of 1-inch increments up to a height of 12 inches—an extension from standard 6-inch models.
For a purchase cost of $1,200, the new system reduced the time it took to calibrate a depth micrometer to about 30 minutes.
“By bringing the standards together, the stabilizing process takes a lot less time,” Warzel says.
Drill pinsAnother process change that cut turnaround times is in the calibration of drill pins used in thousands of gages. New equipment was bought that not only improved set-up times; it also freed up another tool.
The calibration team decided to purchase a laser bench micrometer that is housed in the environmentally-controlled standards lab. The lab is adjacent to the main calibration area and is separated by a corridor with doors at either end. This separation allows the lab to stay at a constant 68 F ±0.5 degree. In this lab, technician Stephen Angelucci stores the standards in temperature-controlled cabinets, like a cigar humidor. These NIST-certified standards calibrate the standards used in daily operations. In this room, Angelucci wears white gloves so that his hands do not give off body heat that will affect measurements. In addition to overseeing the standards lab, Angelucci also checks the diameter of drill pins. He uses the laser bench micrometer to check the pins, which are also known as gage pins. More than 100 sets of drill pins are in use and they have to be calibrated every 56 weeks.
The pins are set in a V-block on the machine’s stage where three locations on the pins—top, middle and end—are checked for concentricity. Each measurement takes a tenth of a second to complete as a thin band of scanning laser light projects from a transmitter to a receiver measuring the shadow made by the tool. The laser system measures to accuracies within millionths of an inch.
But, even this accuracy is not at the same level as the system that it replaced. Previously, a supermicrometer was used to measure the gage pins. The machine is so accurate that breathing near it will cause a change in readings.
Despite its high accuracy, however, it required too much time to complete the measurements. Changeover times from one type of drill pin to another would take about 2–1/2 hours because the system would have to be mastered to a gage block and then zeroed out. The supermicrometer is still used to check gage blocks and thread plugs.
Flight safety toolSome of the most important tools the cal lab verifies are known as flight safety items. Those are the tools that are used to manufacture or assemble critical parts and products. Torque wrenches are one example of those flight safety items, and at Sikorsky there are thousands of them.
Reflecting their importance, and their use in the field, the torque wrenches are frequently calibrated. Currently, the torque wrenches are scheduled for calibration every 16 weeks. If a problem is found, such as torque readings on the low or high end of the tool’s range, the schedule may drop back down to 12-week intervals.
Previously, lab technician Katherine Tvardzik used a manual system to calibrate the torque wrenches. Tvardzik would physically ratchet the wrench up and down the tool’s torque range.
After analyzing the way torque-wrench calibration was being done, the cal lab team discovered that the best solution was to replace the outdated system with a new, automatic torque-calibration system. The new system checks five different places on the tool and ratchets it up at torque levels of 160, 320, 480, 640 and 800, holding the torque and sensing for a click or a breaking of the torque readings.
“This is faster and more accurate,” says Tvardzik. “It used to take me about an hour and now, in about a 10-minute cycle, the system goes through the entire process.”
The torque-wrench calibration machine, purchased for $16,000, has also been useful for other tasks. By using the machine’s swivel indicator stand and special fixtures, the company also uses it as a cable tensiometer. This replaces old methods, including the dead drop in which calibrated weights are hung from a cable.
Going for the goldAfter implementing ACE into its processes, the calibration lab has been able to maintain and improve on the goals to reduce its backlog and queue days. One example of this improvement can be found in the calibrations the lab performs for the gear department. This department sends up to 250 gages a week and is the laboratory’s second biggest customer. “We are at a point now where we have no past-due gages and we are able to turn the gages around in less than a day,” says Papachristos.
In addition, the lab is looking to implement more mistake proofs into the process. To identify problems, Papachristos is working on a customer survey that he hopes will further improve the services the lab provides.
While the improvements made in the calibration lab during the last two years have been impressive, it wasn’t enough to earn the group a gold medal. Under the ACE program, departments are awarded medals: bronze, silver and gold. These medals are determined by market feedback analysis, in this case the tool users, as well as a system that gives points based on how changes were implemented and how they affected backlogs and other metrics.
In October 2001, the group earned its ACE silver status. This year, the group is shooting for gold.
- A new system to root out mistakes and improve processes called achieving competitive excellence was implemented two years ago.
- In the cal lab, 49 process changes were made that reduced the backlog of tools and turnaround times.
- Depth micrometers are now checked with a setting master that has a 12-inch range.
- Bar codes help track tools and get them processed more quickly through the laboratory.
- A torque-wrench calibration machine calibrates the tool in five places and at five different torque levels.
- A laser bench micrometer checks concentricity by measuring drill pins in three places. Measurements are made in a tenth of a second.
Process Changes Involve SuppliersAs Sikorsky Aircraft Corp.’s calibration lab underwent nearly 50 process changes, a number of suppliers were called upon to help. The following is a partial list of the suppliers.
Pratt & Whitney Canada
Fred V. Fowler
Source: Sikorsky Aircraft Corp.