backlog

Backlog refers to a collection of work items that have been identified and approved but have not yet been started or completed. The term is used across industries, including manufacturing, information technology, and software development. In general, backlogs serve as a repository for planned work that organizations intend to execute in the future, allowing teams to separate immediate priorities from long-term tasks.

In manufacturing and supply chain, backlog typically means orders received from customers that have not yet been fulfilled. It is commonly expressed in units or value and can reflect production capacity constraints, supplier delays, or demand fluctuations. Backlog levels are monitored to assess performance and to plan capacity, staffing, and production schedules. The aging of backlog items—how long they have remained unfulfilled—can indicate bottlenecks and service risk.

In software development and product management, backlog refers to a prioritized list of work items such as features, enhancements, bug fixes, technical tasks, and research work. Two related concepts are the product backlog, which represents all approved work for the product, and the sprint backlog, which contains the items selected for a specific iteration. Backlog items are usually described as user stories with estimates and acceptance criteria, and are refined regularly in backlog grooming sessions.

Management practices aim to keep the backlog ordered by value and feasibility, using prioritization methods and estimation techniques. Common activities include refinement meetings, estimating with story points or hours, and converting backlog items into actionable work for development teams. Metrics such as backlog size, aging, and turnover rate help evaluate planning effectiveness and predict delivery.