The process of determining how to successfully replenish inventory throughout the season, in what amounts, through which vendors/shippers, and how frequently — to minimise out-of-stocks, unneeded markdowns, and overall expenses — is known as replenishment planning. In reality, replenishment planning is a complex process that takes into account a variety of factors such as logistics routes, timeliness, availability, and cost. After all, what makes sense is restoring inventory if it arrives late, is the wrong quantity, or is too costly.