Minimising tool switching and indexing times by ant colony optimisation in automatic machining centres

This paper proposes an ant algorithm to minimise the total summation of tool switching and indexing times. The objective of interest is to determine optimal sequence of jobs and position of cutting tools on the tool magazine based on minimum tool switching and rotation of tool magazine. It is shown that this problem is strongly NP‐hard and therefore it is computationally intractable to determine global optimum solution of this problem even for medium‐sized problems. An ant algorithm is proposed in this paper to solve this problem. Performance of the proposed algorithm is compared with multiple start greedy (MSG) heuristic through solving nine‐test problems. The results indicate that the proposed algorithm yields promising solutions to the problem of interest.