The development of multimedia information systems must be managed and controlled just as it is for other generic system types. This paper proposes an approach for assessing multimedia component and system characteristics with a view to ultimately using these features to estimate the associated development effort. Given the different nature of multimedia systems, existing metrics do not appear to be entirely useful in this domain; however, some general principles can still be applied in analysis. Some basic assertions concerning the influential characteristics of multimedia systems are made and a small preliminary set of data is evaluated.