you need to create a new module that inherits sale.order.line. you add the five fields to the sale.order.line object you extend the sale order xml to include your five new fields plus an on-change for each (or if you always have a value in each, then an on-change for the last). The on-change then sums the quantities and puts in the line quantity field.

your other option is to look at product variants - would mean that each size would be a different sale order line - but what you require is already done.

I have this

<xpath expr="//field[@name='order_line']/tree/field[@name='name']" position="after">
                    <field name="talla_xs"/>
                    <field name="talla_s"/>
                    <field name="talla_m"/>
                    <field name="talla_l"/>
                    <field name="talla_xl"/>
                    <field name="talla_2xl"/>

</xpath>

But total quantity not refresh, please share me some function for that, tnks