This research has three big contributions to car manufacturing companies in China. Firstly, it defines how an improvement in product variety impacts operational performance. Second, it explains the impact on operational performance of customization strategies practices. Thirdly, the thesis identifies the relative differences of impact by five types of customisations of the product variety on specific aspects of operating performance. It includes a comprehensive analysis of the literature associated with the effects of product variety and customisation as well as techniques for coping with trade-offs between product variety and operating performance. By adopting a quantitative research method, a survey of 12 car manufacturing sector companies from China was conducted. The objectives and questions of this research is clearly defined and outlines the difference the research is to bring to information. This also establishes theories that take into account the relationship between product variety, customisation and operational efficiency. The project focuses on data collection methods and a questionnaire is designed to be submitted to Chinese car manufacturing companies. This gives the empirical results of this study a detailed debate. Finally, the research is concluded by providing a summary of the results of the work and of the study's theoretical contributions. Effective mass customisation and customer-driven development will offer Chinese carmakers a variety of benefits. The basic results, therefore, have significant management consequences for Chinese car producers to pursue numerous strategies under different product design profiles.