Six Sigma Yield Improvement Project

                                            Six Sigma Yield Improvement Project 


Define Phase 

My name is Ann Coughlan. I am working in a Multi National medical device company and I am the Team Leader for a new product introduced in January of this year. The project is still in the development phase but we have deadlines for various builds and one of our biggest challenges is yield.

 The overall project objective was to achieve a 20% improvement . A team was assembled by me to look at the best way to complete this goal and the first meeting took place on Tuesday 12th Nov 2013 to discuss the plan.

In the Define phase the team agreed to  complete a Project Charter. The team agreed on a Project Charter (see figure1 below 2nd page of project charter)  as a visual reminder of what needs to happen in each stage of the DMAIC process. This,we felt,would guide us through each stage and it would also allow us to add or subtract if necessary as the project progressed.  

Figure 1 Project Charter

From there it was decided to map the process (see figure 2 below "process flow chart") and highlight the area's of concern so that we could focus our energy in those area's. A process map is a visual aid used by the company as part a "work content graph"  which is continuously up dated when a line is asked to produce more units or if for some reason it introduced a step on one of the stations. The high lighted area's on the chart are the stations we looked at from a yield  perspective. We needed to know which stations were causing the poor yield on the line. The chart shows where the issues originated from. 

Figure 2 Process flow chart

Yield

We also decided on a pareto chart (see below figure 3&4) to see what the biggest issues were on the line. It became very evident where the issues were on the line. We were using a gluing method to glue our hubs to the units. The first chart shows a straight mandrel being used and the second one shows a tapered mandrel being used. As you can see from the charts both gave very different  outcomes. There were other issues on the line, but from a pareto stand point our main focus was the  hub gluing station. Th pareto was a very useful tool because it enabled us to focus on the problem area. 

Figure 3 Straight Mandrel

Figure 4 Tapered Mandrel