Apr-Jun.12 - the Nitie

Fixing problem statement to work upon.
Critical to quality (CTQ) tree based on costumers’
needs and requirements.
Problem statements
measurable, since it forming the base for improvement
efforts. Based on the data collected regarding rate of
production and rejections for the products in question
following problem statement is formed.
CTQ tree
Depending upon the nature of the problem, customers
of the project in question are the ultimate customers
who are receiving the products of the company and
paying the bills. For identifying requirements of the
customers, the critical to quality tree being the most
will help to understand the critical quality requirements
of the product. To improve the quality of the product,
these CTQ need to be addressed.
For
Nose-ring
segment
Figure 1: CTQ tree for the castings in question
3.4 Measure phase
During this phase baseline sigma level is calculated and
thus the current situation of the process is ascertained.
Sigma level can be calculated by different methods,
based on type of data. For discrete data Defects per
Million Opportunity (DPMO) number is calculated and
then from the DPMO-Sigma Level table current sigma
level is ascertained.
DPMO =
Where…
No. of Defects X 10 6
(no. of opportunities x no. of units)
No. of defects = No. of rejections (i.e. at least one
defect exists to assign the product as defective)
For
Cooler
plate
No. of opportunities = No. of CTQs and
No. of units = No. of units produced.
The data for two quarters is collected for all the three
products and present sigma levels were ascertained
based on DPMO calculations.
For Cooler plate…
For
Hammer
DPMO =
125 X 10 6
(3 x 8050 )
sigma level as
Vol. 36, No. 2, April-June, 2012
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