Before a project has been identified, we can analyse a subject matter area to explore scope and determine requirements to set the bounds for a future system or project. This is typically appropriate to an early investigation stage such as an IRIS (Initial Requirement Initial Scope). We have experience of analysing large and complex extant systems to identify and challenge existing practice and help realise the client's future vision. We use partitioning strategies to sub-divide large multi-faceted problem spaces into rational, manageable logical components with clear separation of concerns and well-defined interfaces. We articulate a requirement set using use cases or textual requirements. We recognise that high assurance developments will require thorough requirements management and traceability whereas a lightweight approach is more appropriate for experimental and prototype developments. If required we can perform options analysis and assessment.