How is it possible to taken an 80% bit out of your scrap and start turning out parts with very little variation—all within a three-month period?  For Halla Climate Control Canada Inc., it took a management commitment to quality and the technology to support it.  In Halla's case, the technology was automated statistical process control (SPC).

Halla, a joint venture of Halla Korea and Visteon Corporation, manufacturers climate control products for the automotive market.  The company is a leader in the production of underbody refrigerant and coolant lines, accumulators/receiver driers, blower units, and clutch components that are used on clutch-cycling air conditioning (A/C) compressors.

In a vehicle's A/C system, refrigerant is carried through the refrigerant lines in both liquid and gaseous states.  The refrigerant lines incorporate valves for charging the system, pressure switches to regulate the operation of the compressor and a flow restrictor that transforms the high-pressure liquid into low-pressure gas.  The coolant lines circulate hot engine coolant between the engine and the heater core.  Every system is custom-designed for each specific model of vehicle, producing a unique set of dimensions, configurations and performance requirements.

Although the company had been manually recording quality control data and creating control charts by hand at its two plants in Belleville, Ontario, the data wasn't as organized and accessible as the company felt it should be.  Today, during every phase of production for its refrigerant and coolant line products, workers respond to unacceptable process conditions in real time with the help of Synergy 2000 SPC Software.

Halla identifies the significant process characteristics it want to monitor with SPC during its Advanced Product Quality Planning (APQP) stage of a project.  "These are characteristics that could have an adverse effect on the overall quality or performance of our products if they are not carefully monitored and controlled," says Quality Supervisor Shane Davidson.  For example, improper dimensions can impact the assembly and fit of the system; poor connections can cause leaks, loss of pressure, overheating and ultimately a breakdown of the entire A/C system.

Halla's core values with regard to quality, continuous improvement and customer satisfaction have led to certification to ISO/TS 16949 standards, but also present a number of data collection and data management challenges.  One of the more cumbersome aspects of managing production data is keeping track of which files belong to which parts.  Synergy 2000 lets Halla create part files complete with a simple underlying structure for holding the "data tables" for each process characteristic.  The program worksheet is where data is entered into the system.  It displays the precise status of active processes using "traffic-signal"-inspired warning indicators over the computer network.

Some typical process characteristics Halla might identify for SPC include consistency of length in the tube cutting operation, ODs for serrations, couplings and the location where the hose attaches to the tube—a pass/fail visual inspection.  Operators respond to changing process conditions and take corrective actions on the spot, based on the color codes of the warning indicators:  Green for a smooth-running process, yellow for the development of undesirable trends, and red for serious process problems that need to be addressed immediately.  The worksheet also serves as a dashboard for launching other functions such as control charts, reports, messaging, analytical and traceability tools.  Vernier calipers and vernier length gages interface with the software to input measurements directly into the system to free operators from manually inputting the data—a more accurate and efficient way to collect the data.  A variety of other measurement devices such as bore gages are used with the software in the Quality Lab for additional automatic data input.

"Our biggest success has been in the end-forming area, where we create the couplings that will eventually be crimped to the hose," notes Davidson.  "It was an area where we had constant issues every shift:  non-conforming products, scrap, rework through the roof.  Now the end-forming area takes care of itself.  About three months after we implemented the Synergy 2000 software and got everyone on board with how to use it, you could see the scrap rate just drop off.  We improved at least 80%, and rework dropped off with it.  I believe that every process can benefit by using SPC to identify and eliminate special causes of variation, and our end-forming process is definite proof of this.  The key to success is using the information gained."

Synergy 2000 has also helped Halla redirect its appraisal costs.  "Appraisal costs are inherent, but they don't have to be as costly if you're spending your time on the right processes.  We can see which processes are highly capable, where we're spending too much appraisal time, and which processes don't need to be monitored as closely.  We can take that unnecessary inspection time and put it to better use in areas that need more improvement," he adds.

Halla has customized the screen display so that Operators can reference pictures and text files whenever they need to be prompted on work instructions or measurement procedures.  "Operators like the fact that it's very fast and easy to use even if they've never touched a computer before," Davidson points out.  Possibly their biggest hurdle was understanding how control limits relate to specification limits and why they're not the same.  "We explained that spec limits dictate the total range of acceptance on a given characteristic, whereas the control limits are based on the acceptable range in which the tooling can produce parts.  Once the process is in a state of statistical control, with a Cpk value of 1.67 or greater, you don't need to monitor specs anymore because you're looking at a process with very little variation."

Davidson uses the "Engineer Level" of the program to administer the system, giving him change management privileges and analytical tools not available to "Operator level" users.  Recently he has been exploring the functions of a third Synergy 2000 module, the "Manager Level," that offers enterprise-wide monitoring and reporting capabilities.  From the Manager Level PC, he can simultaneously view the status of every characteristic for every part at both Halla facilities, and zoom in on any characteristic he wants to examine in greater detail.  "At any time, I'm able to see what processes are leaning toward the upper limit and what processes are running around nominal," he says.  As a Manager Level user, he can also create a variety of summary, observation, sample and reject reports for review by Halla executives or their customers.  All three levels work together to achieve a highly collaborative quality team.