The Two-Period Travelling Salesman Problem Appliedto Milk Collection in Ireland

摘要: We describe a new extension to the Symmetric Travelling Salesman Problem (STSP) in which some nodes are visited both of 2 periods and remaining either 1 periods. A number possible Integer Programming Formulations given. Valid cutting plane inequalities defined for this problem result an, otherwise prohibitively difficult, model 42 becoming easily solvable by combination cuts Branch-and-Bound. Some entered “pool” only used when it is automatically verified that they violated. Other constraints generalisations subtour comb single period STSP, identified manually needed. Full computational details solution process