Qrb 501 Week 6

After referencing the given data on all three suppliers, it was concluded that Supplier A should be eliminated from consideration as a supplier of our transmission gears.   The reasoning behind this decision was the result of a few key issues. First, this particular supplier has a defective percentage rate of 18%. Secondly, the supplier also had a probability of failure of 55.83%, if all three suppliers were included. Therefore, it was logical to eliminate this supplier from consideration.  
After reviewing the remaining two suppliers, B and C, we discovered that each has at least one sample, which was 20%, or greater beyond desired specifications.   Since outliers can cause deviation of results away from real performance and process outcomes, outliers from each supplier were removed from our calculations and the following were found:
 Supplier C have the gears closest to the target specification and have the lowest probability of failure, 6.02 for this supplier’s median measurement and 42.86% respectively.

 Process Capability (Cpk), which measures how close you are to your target and how consistent you are to around your average performance, is greater for supplier C at 2.62(Graph 1) versus supplier A at 1.58 (see Graph 2).

 In addition, supplier C’s low standard deviation of 0.31, indicates how much less variation there is from their "average" (mean).   Supplier B’s standard deviation is double supplier C’s at 0.60.

                                              Graph 1                                                                 Graph 2
In conclusion, it is this team’s recommendation to offer the manufacturing contract to supplier C as the primary supplier of parts for our company.   In addition, if the business need arises, supplier B can be use as a backup if supplies from C cannot fulfill our production requirements.