We consider the problem of scheduling n tasks subject to chain-precedence constraints on two identical machines with the objective of minimizing the makespan. The problem is known to be strongly NP-hard. Here, we prove that it is binary NP-hard even with three chains. Furthermore, we...

A set of n nonpreemptive tasks are to be scheduled on m parallel dedicated machines with a regular criterion. Chain precedence constraints among the tasks, deterministic processing times and processing machine of each task are given.

In this paper, we analyse the distribution system of an Italian company operating in the ice cream and frozen food industry. In particular, we address the problem of optimally allocating products demand to distribution centres spread over the Italian territory and develop a mixed integer...