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Get More (Products) Out of Your Day

It seems the most common response to a request for help is, “Sorry, I just don’t have the time.” However, a former teacher of mine once said, “We all have the same amount of time to spend (24 hours a day), but it is what you do with it that matters.” The same applies to manufacturing equipment and especially to pick-and-place machines. The owner of a PCB assembly plant has invested in SMT flow lines and intends to produce as many quality boards of the required product mix as possible. But, in reality, there will be a big difference in performance over different SMT lines. Why?

The total available time for a manufacturing line is 365 days per year at 24 hours a day, providing 8,760 hours of manufacturing opportunity. But not all available hours will be used: Holidays, breaks, lack of orders, lack of personnel or electricity, and planned maintenance take up some of those hours. In a planned shutdown the unscheduled time is not influenced by the manufacturing equipment installed.

After subtracting these hours for planned shutdown, a facility is left with planned production time.

Overall Equipment Efficiency

To compare the influence of production equipment characteristics on effective line output (the true number of good products per hour) SEMI has defined overall equipment efficiency (OEE) metric in its SEMI-E79 standard. OEE is divided into three main categories of efficiency losses: Downtime loss, speed loss, and quality loss.

Read the full column here.

Editor's Note: This article origially appeared in the May 2013 issue of SMT Magazine.