Six Sigma Fundamentals: A Complete Introduction to the System, Methods, and Tools

Defects per opportunity is the proportion of non-conformities (defects) within the total number of opportunities in a particular unit. For example, 43 errors (defects) were found in reviewing 445 leasing contracts. There are 5 items that present themselves as possible errors. In other words, the reviewer must make sure that these 5 items are correct. The DPO can be calculated as: 43/445x5 = .019 DPO. The opportunity has to be correlated with the critical to quality (CTQ) requirement. The CTQ characteristic is closely related to the customer, and it is this relationship that we want to maximize, free of any defects. A caution is necessary here. The opportunity identified and calculated can have a direct impact on the sigma value. Therefore, make sure that the opportunity identified and evaluated is the same before and after the analysis, otherwise the experimenter may be comparing apples and apricots.