Abstract: For the adaptive design of the large complex product,the ratio of the time required for new product design by adapting the existing design and the time required for redesign product can be used as evaluation index of design adaptability based on time costs.From the aspect of similarity,design reuse and customized flexibility,the adaptability was measured by retrieving the adaptive tasks of product design,and a new calculation method of design adaptability was proposed.Finally,an example of rail mounted gantry container crane was used to demonstrate the feasibility and practical value of the proposed method.

Key words: adaptive design, similarity, design reuse, customized flexibility