A good NPD process is required to develop products successfully.
Quality function deployment (QFD) is a popular tool to fulfill the task in different phases in NPD.
In order to take into account the impreciseness and vagueness in human judgments and information, fuzzy set theory should be applied.
Due to the fact that people are not willing and capable of handling comparisons properly when there are too many factors, FDM is applied first to select the critical factors.
In order to consider the interrelationship among CAs and ECs and the inner dependence among CAs and among ECs accurately, FISM can be applied first to determine whether the inter-relationship among factors exist or not, and FANP and QFD can be incorporated next to determine the degree of the relationship and to calculate the priorities of the ECs.
The proposed steps are as follows: