Joint Optimization of Item and Pod Storage Assignment Problems with Picking Aisles’ Workload Balance in Robotic Mobile Fulfillment Systems

Algorithm 1

Improved genetic algorithm (IGA).

	Require: P (population), N (population size), Pc (crossover probability), Pm (mutation probability), (iteration number)
(1)	P  Initialize (N)
(2)	for ( = 1; ; ++) do
(3)	P, N, W  Pod_Selection (P, N)
(4)	P, N, S  Pod_Assignment (P, N, W)
(5)	P  Fitness (P, N, S)
(6)	P′  Tournament_selection (P, N)/Offspring individuals selected based on the binary tournament strategy/
(7)	P″  Crossover (P′, Pc, N)
(8)	P″  Mutation (P″, Pm, N)
(9)	P  Preserve_mechanism (P, P″, N)
(10)	end for
(11)	return P