Case Studies: Quality Control Increases Throughput
In the spring of 2004, Mercury Marine (Fond du Lac, WI) introduced the Verado-a six-cylinder, four-stroke 275-horsepower outboard engine. In addition to being the industry's first supercharged outboard engine, it is noteworthy in terms of its quality assurance program.
Typically, outboard engine manufacturers use end-of-the-line hot testing to verify quality. This involves starting each fully assembled engine and letting it run for a given period of time. The downside to this kind of testing is that, with a fully assembled engine, it can be difficult to diagnose the root cause of any failure, requiring greater time and effort to make the repairs. Hot-test stations also tend to be costly, irrespective of the number of defects that need to be repaired. The cycle time required to complete a test typically results in a production bottleneck.
To eliminate these problems Mercury Marine implemented an in-process testing system from Sciemetric Instruments (Ontario, Canada) to both decrease repair costs and increase throughput, a standard approach in the automotive industry.
With any production line, defects can occur at a machining or assembly station because of a damaged sub-component or a problem with one of the assembly machines. The ability to catch a quality problem as soon as possible is important when manufacturing complex products with many production stages.
Mercury Marine's in-process engine testing system includes a number of testing stations located at key points during the manufacturing process where engines can be tested before additional modules are added during assembly. By performing tests before the installation of additional subassemblies, the company can diagnose the root cause of a defect more easily and make necessary repairs. Detecting and addressing a quality issue as soon as it is introduced streamlines the production process and provides for better process control.
Using this approach, Mercury Marine is able to verify that each engine satisfies engineering specifications for emissions, power and sound. Also, it has dramatically reduced the number of hot tests that it performs.
"The Sciemetric-based test systems that we utilize in our Verado assembly process have been vital in improving first past yield, providing data for continuous improvement opportunities, and validating our processes," says Aaron Sagmeister, test engineer for Mercury Marine. "This results in improved throughput, reduced cost and improved quality."
- Adam Cort, Assembly
• An in-process testing system helps avoid production bottlenecks, decreases repair costs and increases throughput.
• The system allows Mercury Marine to perform tests before the installation of additional subassemblies, making it easier to diagnose the root cause of a defect.
• The company has significantly reduced the number of hot tests that it performs.