Enhanced energetic reasoning-based lower bounds for the resource constrained project scheduling problem

► We present three classes of lower bounds that are based on the concept of energetic reasoning. ► The first class includes bounds that are based on the so-called revisited energetic reasoning. ► The second class includes bounds that are based on the concept of reduced instances. ► Finally, the last class of bounds are based on discrete dual feasible functions. ► Our computational results provide evidence that a deceptively simple DFF-based lower bound is effective.