QFD in manufacturing plants

When Covid pandemic disconnected our long-established global trade and supply chain—albeit temporarily (hopefully)— we’re hit hard by a painful awareness that out-sourcing key components entirely to overseas presents a national strategic concern, not just business loss.

So with government encouragement, more US industries are opting to build a new manufacturing base and/or relocating their overseas business to a domestic location. Manufacturing, by the way, was where QFD was originally conceived in Japan, although its application has since expanded to all industries.

Early practitioners and consultants in the US and Europe in the 1980-90s mistakenly believed that the House of Quality matrix (HoQ) was the only tool for QFD. Unfortunately, some are still trapped in this misinformation today. We would like to emphasize to our QFD practitioners today that the House of Quality matrix (HoQ) is neither the start nor the finish of our method: "The HoQ is like a highway interchange between the customer and the engineer. To limit QFD to only this tool is like building the interchange in an empty field without connecting roads." [Glenn Mazur, QFD Institute]

In the past newsletters, we have described in detail the 'customer road' that leads into this interchange—the modern voice of customer (VOC) analysis which is a strong part of Blitz QFD®. With the US industry's renewed interest in relocating or building manufacturing domestically, let us write more about the outbound road—the voice of manufacturing and production. This includes, by the way, service and support businesses that have downstream activities that need to be operationalized in order to assure quality.

Modern QFD for Manufacturing

To begin, let us point you to our QFD bible, Dr. Akao's 1990 edit book from Productivity Press, "Quality Function Deployment: Integrating Customer Requirements Into Product Design". Chapter 5 is "Using Quality Control Process Charts: QFD at the Preproduction Stage." Akao emphasizes the importance of this phase to assure quality, manufacturability, and minimize cost. This is especially important as flexible manufacturing technology has increased the technology skills required and reduced the amount of labor. He also recommends that manufacturing and production join the QFD team at the concept development stage, if not earlier, in order to test advanced materials, new production equipment, software, etc.

When manufacturing and production are integrated at the concept development stage, they are able to input their production requirements into the concept, thus assuring that the concept can actually be built in a high quality and cost effective way. This also allows for balancing with customer needs.

This reminds us of one product that required periodic air filter changes, but for manufacturing convenience the filter was placed behind a panel held by 17 screws. The result was that the customer (facility maintenance) only changed the filter after overheating shut down the production line.

The interface between design and production is the Quality Assurance Table. This table deploys key design targets to production to assure that critical specifications and parameters are held. The table explains the source of the criticality such as safety, customer use conditions, past problems, newness of technology, etc.

Modern QFD for Production

Next, the Process Deployment Table shows which steps in the process are key to holding these targets, such as raw material inspection, machining, assembly, etc. Critical processes can be further analyzed in the Critical Process Analysis Table for process capability, operator error, and other risk factors, and mitigating actions can be determined.

These factors are summarized in the Quality Control Process Chart to identify control methods for production and inspection, based on importance to customer, process capability, and other considerations. This study can also include cause-and-effect analysis of critical areas to assure that characteristics that lead to quality targets are built into the build process.

Performance of these characteristics can be monitored with various statistical methods that are called out in the chart. Based on these, work standards and inspection standards can be set, and deployed to training and other steps.

This is a brief description of some of the modern QFD charts that are created after the House of Quality matrix, to assure that the design intent is fulfilled in the production planning and manufacturing processes. Similar tools can be created for service and software products as well. In addition to Akao's book, these charts are covered in the QFD Black Belt® program.

Thus, as US companies bring manufacturing back home, they must exceed both their past manufacturing (that led to them transferring production overseas) as well as the manufacturing quality that their recent overseas operations have achieved. Otherwise, customers will see their new products as lower quality, and falsely blame the American workers. Product and plant managers must use modern QFD to assure that this does not happen. It is the best method for flowing the voice of the customer down to the plant level.

© QFD Institute | Glenn Mazur