An Improved Discrete Artificial Bee Colony Algorithm for Hybrid Flow Shop Problems - Intelligent Computing for Sustainable Energy and Environment - page 298

the incumbent individual will be accepted. In other words, if either of these two
crossed individuals yields a better makespan than the incumbent individual, then
the better individual will replace the incumbent one and become a new member
in the population; otherwise, the old individual is retained.
3.3 Onlooker Bee Phase
There are NP onlooker bees and each communicates with its corresponding
employed bee. After the probability selection, also called the wheel selection,
a modified variable neighborhood search (VNS) [20] is incorporated into our
algorithm as a hybrid strategy to further improve the performance. We use two
structures of neighborhoods, which are referred to as the insert local search and
the swap local search. The procedures of the insert local search and the swap
local search are given in Fig. 1, where u and v are two positive integers chosen
randomly in the range of [1, n ]. The local search combining both the insert local
search and the swap local search is illustrated as follows:
Step1. Perform the insert local search. If the individual is improved, go back to
step 2; otherwise end the procedure.
Step2. Perform the swap local search. If the individual is improved, go back to
step 1; otherwise end the procedure.
Fig. 1. The procedure of modified variable neighborhood search
If the new food source obtained is better than or equal to the incumbent
one, the new food source will be memorized in the population. The onlooker bee
phase in the IDABC algorithm provides the intensification of the local search on
the relatively promising solutions.
3.4 Scout Bee Phase
As it has been stated in the basic ABC algorithm, the scout bees search randomly
in the predefined space. This procedure will increase the population diversity and