The correlation between quality and production levels

This of course excludes situations where quality is compromised by cost cutting, false economies or lack of control. 

I have learned over very many years that to deliver a product or service at a consistently high quality standard requires investment in staff training, processes (what you do), procedures (how you do it) and ensuring the most effective metrics, control and feedback mechanisms are in place. There are no short cuts! However, even with all this in place there is no guarantee that the expected level of quality will be achieved.

If you have experienced quality issues, then how did you address them and how successful were you?
Has one particular element of your approach been truly successful?

I have found that the ability to sustain consistently high quality metrics is most at risk during the introduction of a new product or service or a ramp up or slow down scenario. The ideal situation being consistent demand with a positive momentum.

A new product introduction or production ramp up usually incurs a learning curve and it is not uncommon for quality to be impacted. Conversely during a slowdown, when capacity typically exceeds demand, concentration suffers with a consequential impact on quality.

It requires a culture of operational discipline and attention to detail to combat these and therein lies the management challenge.