Tuesday, September 2, 2008

Six-Sigma - Motorola's Learns to Measure Quality

Supply chain manufacturing concepts often seem to emerge fully formed out of nowhere, and while there have been numerous short-lived trends du jour, in reality the legitimate best practices have gestated for many years, sometimes for decades. There's nothing new about lean manufacturing or the Toyota Production System, for example, even though they're currently popular buzzwords. The TPS, after all, emerged in Japan shortly after World War II ended, and in fact was based on concepts popularized even earlier in the twentieth century by Henry Ford. So even though lean is at the top of many people's minds these days, the only thing truly new about lean is the acceptance it's finally gained in the United States.

Another manufacturing concept that is frequently associated with lean is Six Sigma, a structured, quality-centric approach to manufacturing. It began at Motorola in the 1980s as a way of improving the quality and reliability of its products, which would enable the company to deliver a consistently high level of customer service. Based on quality initiatives developed by the Japanese, Motorola's Six Sigma program—like the TPS—involved every employee in the company.

Six Sigma is a measure of quality that strives for near perfection, which is defined as no more than 3.4 defects per million opportunities.

Motorola learned from the Japanese that "simpler designs result in higher levels of quality and reliability," explains consultant Alan Larson, a divisional quality director at Motorola when Six Sigma was launched. The company also learned that it needed to improve manufacturing techniques "to ensure that products were built right the first time."

The term Six Sigma refers to the idea of near perfection, defined as six standard deviations between the mean and the nearest specification limit. In practice, this means a product or process can have no more than 3.4 defects per million opportunities. Six Sigma, like the SCOR Model, focuses on five areas: define, measure, analyze, improve, and control. Six Sigma programs typically use statistical process control (SPC) tools to monitor, control, and improve a product or process through statistical analysis.

To achieve the desired result of enabling continuous improvement, rather than merely putting a temporary bandage on a problem, Larson recommends that every department, group, and unit within a company complete the following six steps:

* Identify the product you create or the service you provide.
* Identify your customers, and determine the customers' needs.
* Identify your suppliers and what you need from them.
* Define your process for doing the work.
* Establish metrics for measuring the goodness of your process and feedback mechanisms to determine customer satisfaction.
* Ensure continuous improvement by establishing a team that measures, analyzes, and completes focused action items.

Proponents of the Six Sigma approach typically cite its lack of ambiguity as a major plus. The Six Sigma methodology applies a mathematical precision to what might otherwise be highly imprecise supply chain processes. A corollary benefit comes when a company insists on getting commitment from every employee, and requiring everybody to focus on the better good for the entire supply chain.

"Getting our business units to accept change has been accelerated because we're talking a common language and common methodology through Six Sigma," observes Lori Schock, site supply manager with Dow Corning, a manufacturer of silicone-based products. "It removes the doubting Thomas attitude because it is a common process based on facts."

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