A design is the concept of or proposal for an object, process, or system. Design refers to something that is or has been intentionally created by a thinking agent, though it is sometimes used to refer to the nature of something – its design. The verb to design expresses the process of developing a design. In some cases, the direct construction of an object without an explicit prior plan may also be considered to be a design. A design is expected to have a purpose within a certain context, usually having to satisfy certain goals and constraints, and to take into account aesthetic, functional, economic, environmental or socio-political considerations. Typical examples of designs include architectural and engineering drawings, circuit diagrams, sewing patterns, and less tangible artefacts such as business process models.