Modular product development plays an important role in helping manufacturing companies provide product variety rapidly in achieving competitive advantages. The development of product options plays a significant role by providing a selecting list for customizing, and has a key impact on the development of modular products. A process for product options development has been developed to guide the activities of determining product options and their values. And mathematical models have been brought forward to support decision-makings within the proposed process. A prototype system based on this process and mathematical models has been developed and tested in a machine manufacture plant, with satisfactory results.