We study the problem of scheduling unit time tasks of two types on m parallel identical machines. For each type, given numbers of tasks are required to be completed by the specified deadlines. These tasks leave the system at the deadlines. The in-process inventory capacities are given. The objective is to construct a schedule that minimizes the number of changeovers occurring between the tasks of different types. This problem arises, for instance, in the production of gear-boxes on transfer lines and in the tobacco industry. Pattloch and Schmidt [Discrete Appl. Math. 65 (1996) 409
Mikhail Y. Kovalyov, Marcus Pattloch, Günter