I have been facing this question from the people in software industry that whether Six Sigma is applicable to their industry or not.
They ask whether the goal of 3.4 defects per million opportunities can be applied to final software that they are making for their Clients. Should they be allowing 3.4 mistakes in a million lines of code that they have developed? Even achieving this goal would NOT result in getting the customer's satisfaction because their code would just refuse to run.
So is Six Sigma really meant for the software sector?
Specifically for the software sector, we cannot view Six Sigma as just a mathematical goal of 3.4 defects per million opportunities. There are other views about Six Sigma which are equally important. I define Six Sigma as a management philosophy or technique to improve the business processes on the whole.
If I limit myself to the definition of "3.4 defect per million opportunities" and try to apply it over my final product, then I am missing out on the bigger picture. I am committing the same mistake that the earlier quality related concepts have done and that is to just focus on the end product.
If I am applying Six Sigma to a software company, I would rather ask why a certain defect is coming up in the program. I would be asking on how the software development cycle time could be reduced. How can I reduce the number of iterations between the software developer and the tester? How can I collect the customer's requirements in the most efficient and effective way so that there is no "reworking"? The "reworking" normally takes place because we have not been able to capture all the requirements of the customers at the very first time.
When I apply Six Sigma to a software company, my focus is on the reduction of the cycle time or the man hours or the cost which goes into the entire business process of making the software. This process starts right from the requirement