Bargaining approach for efficiency assessment and target setting with fixed-sum variables

•Fixed-sum scenarios in which the sum of a variable over all DMUs is constant are addressed.•A bargaining problem is defined considering each variable of each DMU as a player.•This is a novel, bottom-up approach that searches for an agreed overall target projection.•The Nash bargaining solution, with its interesting properties, is proposed.•An efficiency score based on modified Enhanced Russell Graph efficiency measure is proposed.