The sigma values of steps, therefore, are cumulative not independent. The chart below shows how “accurate” or error free a multi-step process is. It’s obvious that the more steps the process has the harder it is to achieve an overall sigma of six-sigma.
So when reviewing a process for patients one the initial steps when mapping the process and looking at accuracy is to determine whether a step can be eliminated. Not only will it cut down on wasted time but it will improve the accuracy of the process exponentially.