Local branching: a tutorial

Mixed-Integer linear Programming (MIP) plays a central role in modeling difficult-to-solve (NP-hard) combinatorial problems. However, the exact solution of the resulting models often cannot be carried out for the problem sizes of interest in real-world applications, hence one is interested in effective heuristic methods. Although several heuristic and metaheuristic frameworks have been proposed in the literature for specific classes of problems, only a few papers deal with general-purpose MIP heuristics, including [1], [5], [6], [8], [9], and [11] among others.