Multicriteria Pythagorean fuzzy decision analysis: A hierarchical QUALIFLEX approach with the closeness index-based ranking methods.

•A new closeness index-based ranking method of PFNs is presented.•A novel concept of interval-valued Pythagorean fuzzy set is proposed.•A new interval-valued Pythagorean fuzzy distance measure is presented.•A new hierarchical Pythagorean fuzzy QUALIFLEX method is developed.•The proposed method is further extended to manage heterogeneous information.