Design–build (or design/build, and abbreviated D–B or D/B accordingly), also known as alternative delivery, is a project delivery system used in the construction industry. It is a method to deliver a project in which the design and construction services are contracted by a single entity known as the design–builder or design–build contractor. It can be subdivided into architect-led design–build (ALDB, sometimes known as designer-led design–build) and contractor-led design–build.