Abbrev. for Jackson system development. A proprietary structured method for the analysis and design of data processing and real-time systems, originally devised by Michael Jackson in 1983. JSD is fully integrated with JSP (Jackson structured programming). The JSD notation covers entity structures (similar to SSADM entity life histories), and network diagrams connecting entity and process structures. Rules assist the designer to iteratively structure and sequence the design and to transform and trace requirements into the software design.