Mass customization capabilities enable firmas to design, produce, and deliver a high volume of differentiated products that meet specific customer needs in a timely manner and to mass-production prices. A critical part of mass customization is simultaneously achieving customer responsiveness, cost efficiency, and high volume production in the manufacturing system. This research describe mass customized and provides a framework to understand the relationship among time-based manufacturing practice, mass customization, and value to customer. It involves the development of an instrument to measure mass customization. Data were collected from 303 manufacturing firms of various size, location, and industry to develop the instrument and test the relationship in the framework. The primary research method was structural equation modeling using LISREL. The study indicates thaat firms with high levels of time-based manufacturing practices have high levels of mass customization aand vaalue to the customer. Also, firms with high levels of mass customization have high levels of value to customer.