The objective of this study is to investigate the approaches utilised by external decision-makers in their evaluation of the different facets of performance of manufacturing organisations, operating as open systems. In process, important linkages which exist among relevant performance parameters are explored. The types and frequencies of performance measures used by the sampled Portuguese financial analysts are compared using factor analysis and multiple regression analysis. Results tend to underscore the significance of the collective performance of all subsystems of the manufacturing system. Based on the findings of this research, implications focusing on the management of organisational performance systems are identified.