Semiotics treats organisations as sign systems and concerns the study of organisations, human communication and information systems. It is used as an approach to requirements engineering that develops integrated structural and behavioural models. This paper focuses on the MEASUR approach, which has been successfully applied to well-understood, bounded problems. However it is difficult to apply MEASUR systematically to complex, poorly bounded problems. This paper investigates these problems and suggests how the approach could be improved by using Natural Language Processing tools to assist the process.