A MILP model for an extended version of the Flexible Job Shop Problem
  A MILP model for an extended version of the Flexible Job Shop Scheduling problem is proposed. The extension allows the precedences between operations of a job to be given by an arbitrary directed acyclic graph rather than a linear order. The goal is the minimization of the makespan. Theoretical and practical advantages of the proposed model are discussed. Numerical experiments show the performance of a commercial exact solver when applied to the proposed model. The new model is also compared with a simple extension of the model described by \"Ozg\"uven, \"Ozbakir, and Yavuz (Mathematical models for job-shop scheduling problems with routing and process plan flexibility, Applied Mathematical Modelling, 34:1539--1548, 2010), using instances from the literature and instances inspired by real data from the printing industry. 
Ernesto G. Birgin, Paulo Feofiloff, Cristina G. Fernandes, Everton L.   de Melo, Marcio T. I. Oshiro and D\'ebora P. Ronconi
cs.DS cs.DM