Importance of Nominal Group Technique in a six sigma project

In a six sigma project there are times when data can’t be collected on all the Xs(Potential Causes) and rest of the potential causes are to be dealt by process door approach.

Before a black belt starts finding out solution for all data and process door Xs they need to identify significant Xs from process door Xs as well. For data door Xs Hypothesis testing was used and for Process door Nominal Group technique can be used to identify significant Xs.

The nominal group technique (NGT) is a group process involving problem identification, solution generation, and decision making. It can be used in groups where everyone's opinions are taken into account (as opposed to traditional voting, where only the largest group is considered). The method of tallying is the difference. First, every member of the group gives their view on identified process door causes (Xs), with a short explanation. Then, duplicate causes (Xs) are eliminated from the list, and the members proceed to rank the causes, 1st, 2nd, 3rd, 4th, and so on.

Sum all the ranks given by individual of the Potential Xs and Pick up top one or two Xs to find out solutions.

For Example :

In the example above ‘System issues’ and ‘Lengthy’ forms are the significant Xs to be worked