Every business concern is made of a number of interrelated processes. When inputs are made to traverse through a process, they result into certain outputs (products & services) serving either internal or external customers. A process is termed as industrial or commercial depending on whether 80% or more of the values derived are from machinery or from human activity, respectively. No matter how perfect a process is, no product/ service will come conforming to exact targeted specifications. It would always vary. However, when it varies within certain Lower Specification Limit (LSL) and Upper Specification Limit (USL) as acceptable/ agreed to or specified by the customers, then it is considered to be defect free or quality product/ service. Further, every opportunity of delivering a product/ service is also wrought with an opportunity for the occurrence of defect. When the Defects Per Million Opportunity (DPMO) doesn’t exceed 3.4, the process is said to have met Six Sigma level. And Mumbai Dabbawalas’ DPMO is less than 3.4 or precisely, it is 2!