Production Planning
Sizes share a marker and nest into each other's gaps. Colours cannot share anything — each one needs its own lays.
— no.
Cutting lays to complete the order
Lays are computed from total quantity and assume the size ratio divides evenly into the marker combinations, which real order breakdowns rarely do — an awkward ratio forces short lays or leftover single-size markers, and both erode the saving shown here. Marker efficiency at each grouping level must come from your own CAD system on the actual pattern set rather than from these defaults, since the gain from combining sizes depends entirely on garment shape. Grouping also has costs the fabric saving does not capture: more markers to make, longer lays to spread, and a bundle-sorting problem in the sewing room that grows with every size added to a marker.
Garment Cut-Plan Size & Colour Grouping Optimizer — free, with the formula and a worked example, at Textile School.