<div class="htmlview paragraph">This study shows that to minimize the information content at an early stage of a design process, three types of compliance are required, namely range, certainty, and requirement compliances. Range compliance measures the average belongingness of a numerical range to a vague linguistic class. Certainty compliance measures how clearly a piece of design information is known or given. Requirement compliance measures how strongly a design alternative fulfills the linguistically defined design requirement or range. To demonstrate the effectiveness of the method, a case study that deals with the selection of optimal materials for a car body is presented. A computing tool is also developed to practice the method using computers.</div>