The paper introduces systems methodologies to illustrate the span of systems engineering activities and the system management structure appropriate to creating a complex and enduring system. Information/decision/action (IDA) systems provide a vehicle to demonstrate a variety of methodologies in operation. This class of system includes individual humans, companies, governments, computer-based data systems and, paradoxically, the system design/management team intent on creating the respective systems themselves. Systems are viewed as having seven ages: conception, design, development, implementation, transition utility and senility (which is followed by replacement). System creation invokes five subsystems: the operational facility, two development subsystems concerned with test-and-integration and incompany support, and two deliverable inservice subsystems for user/operator training and through life maintenance. System creation team structure is shown to comprise operations analysis, requirements analysis, system design, equipment engineering, software engineering, test and integration, and installation and commissioning; the systems approach emphasises the first three of these in particular, to reduce the generation ofab, initiodesign errors. Functional decomposition and design option tradeoffs are demonstrated by example, and the establishment of end-to-end system dynamics is introduced using the ISO open system interconnection philosophy. System management organisations are outlines, and the allocation of resources by time within the project team structure it explored pictorially. Transition into operational use is highlighted as an area of special concern and, finally, the key issues of the systems management approach are identified.