A well-planned merchandise assortment should consider several factors: quality, price range, choice of national vs private brands, timing, product life cycles, variety of product lines, and assortment strategies of breadth vs depth. An assortment plan can be developed using a basic stock list or model stock plan. The model stock plan aims to plan an ideal assortment including staple goods, fashion goods, and seasonal goods based on predictable factors like classification, price, material, color, and size. Planning fashion goods assortments is particularly challenging due to many style and vendor choices and short lifecycles of fashion items.