Supplement, November 2000

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Improved Productivity is Just a Few Steps Away

by Kevin Zuege

Today’s economy requires insulating glass (IG) manufacturers to be as efficient and productive as possible, while keeping costs under control. This is not always an easy task, but there are a number of steps you can take to help ensure that you are running the most productive operation possible.


Productivity Measurement

The first step is to measure and track your current procedures. To accurately measure productivity, three separate, but related, elements need to be considered. They are average throughput per shift (ATPS), peak throughput per shift (PTPS) and labor efficiency. Few manufacturers routinely track these numbers, while those who do, often reduce their costs.

The first two elements, ATPS and PTPS, are tied to total throughput. Total throughput is the volume of IG units that needs to be produced in a certain time period to meet sales demand. The time period measured can be a year, month, week, day or a single shift. Determining the total throughput capacity of the IG operation is needed to ensure your staffing and equipment meets your requirements.

Once the average throughput per shift and peak throughput per shift needs are identified, and the IG process has been rationalized to meet those needs, the third element to be measured is labor efficiency.

Labor efficiency is measured by converting the average throughput into “units per man-hour” (UPMH). The UPMH can then be compared against previous time periods (years, months, weeks or shifts), or against other manufacturers using the same type of system. It can sometimes even be compared to a manufacturer using another type of system. Therefore, efficiency is defined as the total IG units produced in a period divided by man hours worked in that same period.

These three simple measurements are the basis of numerical models, which can provide considerable insight into your IG operation (see box on page 9).


Improving Your IG Unit Operation

The next step is to answer the following sample questions to help you measure, compare and improve your IG unit fabrication operation.

     Is my current system able to handle a peak volume of 1,650 units/shift?

     How should I plan to handle the transitions from 1,100 average to 1,650 peak-overtime, Saturdays, hires and/or layoffs?

     Is my average efficiency of 21.5 UPMH a figure of which I should be proud?

     If we plan to grow by 5 percent next year, what provisions will I need to take to ensure throughput needs will be met, which also will reduce unit costs year after year?

These examples are intended to help demonstrate the simplicity of this tool.


Line Type Operators Cycle Time (secs.) Throughput/shift UPMH
Current 8 2@33.4 1375 21.5
TAPE 3 2@45.9 1000v 41.7
Two-sided with PLC conveyor and two presses 5 2@39.8 1154 28.9
Two-sided standard 7 2@37.5 124 21.9

Once a baseline for your current system is identified, setting improvement targets is the next logical step toward cost reduction and/or increased capacity. Within your particular chosen system, you can then compare your operation’s performance to performance standards expected with that system.

The form below was developed by our company and allows the IG supervisor or plant manager to document productivity baselines for both total throughput (peaks and average) and UPMH. The form is for use with Swiggle® Seal, but can be adapted easily for any IG edge seal or spacer system and the associated operator positions. It also works as a checklist to help with operator- specific staffing, which is necessary in determining the man-hours portion of the equation.

Further comparisons allow for labor benchmarking across the variety of edge seal systems on the market. Should you need to explore changes to your process, layout or equipment, summarize your system’s performance parameters as a starting point. An example of this summary is shown above to illustrate how a simple self-audit can help with next step planning and activities.

At this point, research and action are required to achieve your goals.

Sample Measurement

Suppose you need to produce 660,000 IG units for the next year and that your sales peak (during the summer months) demands a production increase to 120 percent of the average volume. Based on past experience, you determine that you have eight operators on each of two shifts planned to make this volume. 

The following three simple calculations will result in the measurements needed as a basis for improvement:

Total Throughput
660,000/year, or on a shift basis:
660,000/yr. x 1 yr./480* shifts = 1,375 IG units per shift

Peak Throughput
1,375 x 1.20 (20 percent greater) = 1650 units per shift
Note: If 1,650 is peak and 1,375 is average, there are likely to be lows of 1,100 units per shift.

One shift with eight operators/shift = 8 x 8 man hrs/operator = 
64 man-hrs/shift 1,375 IG/shift x 1 shift/64 man hrs = 21.5 UPMH

*480=work days per year


Kevin Zuege serves as director of technical services for TruSeal Technologies Inc. based in Beachwood, Ohio.



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