Multi-stage appointment scheduling for outpatient chemotherapy unit: a case study Asma Bouras, Malek Masmoudi, Nour El Houda Saadani, Zied Bahroun and Mohamed Amine Abdeljaouad RAIRO-Oper. Res., 55 2 (2021) 589-610 Published online: 09 April 2021 DOI: 10.1051/ro/2021025