Dominoes domino sets commercially available are double six (with 28 tiles) and double nine (with 55 tiles). Larger sets exist and are popular for games involving several players or for players looking for long domino games. The number of tiles in a set has the formula formula_1 for a double-"n" set. The most popular type of play are layout games, which fall into two main categories, blocking games and scoring games. The most basic domino variant is for two players and requires a double-six set. The 28 tiles are shuffled face down and form the "stock" or "boneyard". Each player draws
Six Sigma can be described by a "sigma" rating indicating its yield or the percentage of defect-free products it creates—specifically, within how many standard deviations of a normal distribution the fraction of defect-free outcomes corresponds to. Motorola set a goal of "six sigma" for all of its manufacturing. Six Sigma doctrine asserts: Features that set Six Sigma apart from previous quality-improvement initiatives include: The term "six sigma" comes from statistics and is used in statistical quality control, which evaluates process capability. Originally, it referred to the ability of manufacturing processes to produce a very high proportion of output within specification. Processes that