Quality Scan: Using Statistical Process Control to Manage Your Suppliers
By Dan Heimann
San Jose, CA
In today’s competitive environment, suppliers must effectively manage the supply-base relationships and deliver a high-quality product to the customer on time. MASS Precision has learned a lot about the rigors of competition and the importance of communication and quality in its nearly three decades.
MASS is one of the few remaining stateside companies offering vertically-integrated metal fabrication and manufacturing expertise from product design, prototyping, pre-production and high-volume production runs, through testing, distribution.
With 250,000 ft2 (23,225 m2) across four sites, product manufacturing and assembly are the core services that we offer to a broad range of multinational OEMs in Silicon Valley and the global marketplace, including Southeast Asia, China, Europe and Mexico. We’ve been in business for 28 years. For 23 of those years, we were in the sheetmetal manufacturing and assembly business. During the last five years, we have increased our footprint into new areas such as automotive, medical, and military.
An example of our capability can be seen in the extremely high-precision guide assemblies that we make. They are used to aim gamma beams during cancer therapy. These instruments are used to target and remove cancer cells on a cellular level—precision is critical. The majority of our production is completed in-house, with one exception, plating.
Due to state and local regulations, we use outside suppliers to plate our products. Because our customers require us to maintain a consistent plating thickness of 0.0003" (0.0076 mm), we needed to develop better communications with our suppliers. We needed to validate that they deliver the products to the precise specification required, and we needed a mechanism to communicate to our suppliers before their products went out-of-control, thereby reducing scrap, rework, and lost productivity.
Our goal was not just to improve the quality we received from our suppliers. We also wanted to improve our relationships with them.
Synergy 2000 software gave us the tools to better measure and analyze the quality of the plating we were receiving using SPC data. This gave us the definitive objective measurements, in real time, to improve quality from our suppliers. Being able to reliably collect data facilitates communication between MASS and its supplier base.
Before MASS started using Zontec SPC, we tried different forms of data collection: spreadsheets, manual data logs, etc. These methods were found to be ineffective because suppliers were not receiving live information about their plating process before defective parts were processed. Now, when we see a supplier’s process trending toward an out-of-control state, we immediately communicate with them to bring the situation back under control. We have reduced defects related to plating thickness to nearly zero and reduced our customer rejects due to plating to less than 1%.
The savings in MRB meetings, DMR processing and scrap costs have been substantial. Our company and our customers, however, are not the only ones to benefit.
Eventually we were able to show our suppliers they could save money and improve their process with the data we collected. Once our suppliers were onboard, their processes steadily improved. Because we are saving our suppliers time and money by reducing rejected products, we have found that they have become our advocates in the SPC process.
This has become a win-win situation for both parties and now some of our suppliers are considering implementing these internal SPC controls.
In order to meet the customer requirements for such tight tolerances, we developed close relationships with our suppliers. Based on objective data, we were able to qualify select suppliers for top-tier customers.
In addition to monitoring our existing supplier base, this has proven to be a fast and cost-effective tool in qualifying new suppliers.
Because of the proactive approach to quality, MASS and its suppliers work together to improve the process. Auditing can be done real-time by reviewing statistical data.
Meeting production deadlines is important, but delivering quality products to our customers is our most important job. We found SPC to be a viable measurement tool with many benefits related to improved quality, and as a bonus, it can improve relationships with your suppliers. ME
This article was first published in the July 2012 edition of Manufacturing Engineering magazine. Click here for PDF.