The document discusses mix planning in media sales and distribution. It describes the process as assigning inserts like advertisements and media issues to customer contracts, then creating issue mixes which are alternative bills of materials for media issues. The key steps are: 1) Assigning inserts to contracts manually or from advertising orders, 2) Grouping customers for insert planning, 3) Using insert planning to assign inserts to contracts for a media issue, 4) Creating issue mixes based on the planned insert assignments. Issue mixes allow operative processing and delivery of inserts together with media issues to customer groups.