particularly concerned about control of adhesive volume in the tube, thus their technical evaluation will entail
analysis of the machines process capability for precise volume filling.
SSI and their surgeon advisers have determined that each tube must be filled with between 33.5 and 38.5 grams
of the adhesive. An over-filled tube would deliver more active ingredient than the patient can tolerate and side
effects may occur. An under-filled tube would deliver inadequate adhesive to properly close the incision,
requiring the surgeon to intervene with sutures – a costly and time consuming alternative.
Two filling machine suppliers, Fill-N-Seal Corporation and Acme Filling Inc. are competitively bidding to supply
the automated filling machines to SSI. As a final test SSI has asked for 50 filled tube samples from the two
suppliers, each filled using the machine design the companies are proposing. SSI has evaluated each filled tube
by precisely weighing the contents; the results of the test are presented in the two tables in Figure 1. The
shaded table contains the results from Fill-N-Seal and the un-shaded table contains the results from Acme
Filling. Both sets of data are normally distributed about the mean.
FIGURE 1
Fill ‘N Seal Results (in grams)
Acme Filling Results (in grams)
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1. (16 points) Judging only by these data sets, are the two companies offering machines with capable filling processes? Which supplier should SSI prefer and why? Substantiate your answer using both mathematical analysis and a graphical representation. i)Fill ‘N Seal Corporation Graphically looking for normal process curves with Mean indicated non-centered (above) to spec for both vendors. Should also show USL and LSL values on the graph. When compared to Acme, FNS curve should show a wider peak than Acme, and indicate potential for more data points outside specification (i.e. right tail farther above USL for FNS).
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