Group scheduling in flexible flow shops: a hybridised approach of imperialist competitive algorithm and electromagnetic-like mechanism N. Karimi a , M. Zandieh b & A.A. Najafi c a Faculty of Industrial and Mechanical Engineering, Qazvin Islamic Azad University, Qazvin, Iran b Department of Industrial Management, Management and Accounting Faculty, Shahid Beheshti University, G.C., Tehran, Iran c...