Since the introduction of software measurement theory in the early seventies it has been accepted that in order to control software it must first be measured. Unambiguous and reproducible measurements are considered to be the most useful in controlling software productivity, costs and quality, and diverse sets of measurements are required to cover all aspects of software. A set of measures for a rule-based language RULER is proposed using a process which helps identify components within software that are not currently measurable, and encourages the maximum re-use of existing software measures. The initial set of measures proposed is based on a set of basic primitive counts. These measures can then be performed with the aid of a specially built prototype static analyser R-DAT Analysis of obtained results is performed to help provide tentative acceptable ranges for these measures. It is important to ensure that measurement is performed for all newly emerging development methods, both procedural and non-procedural. As software engineering continues to generate more diverse methods of system development, it is important to continually update our methods of measurement and control. This thesis demonstrates the practicality of defining and implementing new measures for rule-based systems.