336 Process Techniques for Engineering High-Performance Materials
condition envelope that is likely to generate undesirable levels of
by-products or defects. Compare this to the envelope of conditions
that will produce the product at an acceptable prot. If there is too
much overlap, consider redesigning the process or dropping the
business.
• Install safeguards to ensure that production never ships a batch
that was made during an excursion into a dangerous part of the
process window.
• Automatically record and chart the process conditions on a con-
tinuous basis. Require a review to generate a certicate of com-
pliance to ship each lot.
• Periodically screen for these by-products to ensure that they are
always below the danger levels that hav ...