reorder

Reorder is a general term with several related meanings centered on arranging items in a different sequence or returning them to a previous arrangement. As a verb, it commonly means to place another order for goods or supplies after existing stock has been used or will soon be needed. In everyday use, to reorder can also mean to rearrange items on a list, shelf, or workspace.

In logistics and inventory management, the term has a more formal sense. Reorder typically refers to initiating a new purchase order when stock falls to a defined level. The concept is linked to the reorder point, a threshold that combines expected consumption during lead time with safety stock to avoid stockouts. Related concepts include the economic order quantity, which aims to minimize total ordering and holding costs, and reorder policies that specify when and how much to order.

In computing and data handling, reorder describes changing the order of elements in a collection, such as a list or array. Reordering can be user-driven, as when a user drags items to a preferred sequence, or algorithm-driven, such as during sorting, prioritization, or metadata organization. Sorting is a common form of automated reordering that arranges elements according to a defined criterion, while preserving or altering the relative order of items depending on stability of the algorithm.

In mathematics and related fields, rearranging the order of elements in a sequence or set is a standard operation, though the term reorder is not usually a formal technical label. The concept underpins permutations, which describe all possible reordering of a finite set, and is connected to the study of order relations and symmetry.

See also: reorder point, order quantity, permutation, sorting.