We think this article on the i Six Sigma website is great.
The problem was fairly straightforward but had been unresolved for years. A manufacturer of plastic cups has wide variation in the final weight of each cup. To avoid making too many cups that fell below the customers’ accepted standard, on average each cup was made 1 gram heavier than it needed to be. This obviously meant that more resin was used than needed to be, if each cup was produced to a more standard weight.
The article takes you through each stage of data collection and analysis, in order to explain how the six sigma team went about resolving the problem. No one solution was found, but by eliminating one identified fault in the process, or equipment, after another, eventually $100,000 in savings were made. Good job.