Arnold and helga decide to start selling homemade jewelry on etsy to earn some extra income. however, the materials they use are expensive, and it takes them a long time to finish each piece of jewelry because they bicker about how it should look. in short, their process is not efficient. their daughter phillipa suggests that they design the pieces before they start making the jewelry to help increase their productivity. they are able to make the jewelry more quickly and decrease their average total cost of production. when arnold and helga are able to expand the size of their operation, they are able to experience –.