This paper introduced a parametric workflow for the design of tensile structures, encompassing form-finding, patterning, flattening, and geometrically nonlinear structural analysis of cables and membranes, and how these design steps can be sequenced and iterated. The concepts of parametric design and visual programming languages were outlined, with a particular focus on structural design. The implementation of these concepts was straightforward, and the paper explained their application into a new Grasshopper plug-in, called BATS -basic analysis of tensile structures, capable of performing the full design cycle of this type of structures.