TiNorm: Simple Process Qualification

Using TiNorm you can calculate with confidence the range of a process output.

For example you can state with 95% confidence the range which covers 99% of your process output. 

This can form the basis for qualifying a process, a product or a service offering. 

It moves you from abstract notions of quality to an easily understood and firm statement about your performance and reliability. It allows you to communicate directly to your customer and to your stakeholders. It allows you to discuss clear expectations with your suppliers not only about the performance levels of the supply items but about the effectiveness of their processes. 

Using TiNorm is simple: Input your sample data, test the assumption of normality and then calculate the tolerance interval. The output is easily understood. 

Example: To determine with 95% confidence the force range in lbs required to peel open 95% of blister seal packs.  

A packaging process forms a seal. The seal is tested using a peel test to ensure that the force required to open the seal is within the specified tolerance (not too hard to open - but yet force enough to make sure it does not leak).  12 seals are tested generating the following data (in lbs force):

1.930 2.062 2.126 2.049 2.092 1.998 2.030 2.049 1.798 2.011 1.937 1.939  

The assumption of normality is tested and cannot be rejected and the program then calculates with 95% confidence that 95% of the blister seals will have a peel strength between 2.284 and 1.719 lbs force on a standardised test piece. The process technician is then assured with a known degree of risk and under known conditions that the process is suitable for its intended use and he communicates that by means of a report to management for their approval.