The sweater is worked in the round, from the top down.
First, work back and forth with both raglan increases and increases for neckline. Then gather the work and knit in the round, continue with raglan increases and stranded colourwork knitting according to chart.
When all increases have been made, divide the work for the body and sleeves and finish each part separately. Finally, pick up and knit stitches along the neckline and knit the neckline.