Structured systems analysis and design methods have been widely used in recent years in the specification of requirements for information systems. The development of techniques such as data flow diagramming and entity modelling and the supporting Computed Aided Software Engineering (CASE) tools have been applied since the 1970s in data processing environments. More recently, such methodologies have been applied to manufacturing systems through programmes such as IDEF. A research project is detailed which has identified the development needs for the application of structured methods to flexible manufacturing. A structured methodology for tool management information systems is outlined, together with the role of supporting CASE tools. The methodology models the current information systems associated with tool management, and guides the user in the generation of a requirements specification. The main stages in the implementation of the methodology are described, together with examples of an industrial application within a collaborating advanced manufacturing company.