<xsl:template match="xml">
  <xsl:apply-templates select="factory">
      <xsl:with-param name="leftW" select="$Widget_quota" />
      <xsl:with-param name="leftG" select="$Gadget_quota" />
  <xsl:apply-templates select="factory">
</xsl:template>

(having trouble applying
http://www.stylusstudio.com/xsllist/200211/post11130.html)

Okay, assuming the following input:

<xml>
 <factory x="A" capacity = "3" />
 <factory x="B" capacity= "5" />
  <factory x="C" capacity = "3" />
  <factory x="D" capacity = "2" />
  <factory x="E" capacity = "2" />
  ...etc...
</xml>