Abstract: A mixedinteger linear programming (MILP) formulation is presented for scheduling of nonsequential multipurpose batch plants with raw material inventory constraints. The proposed formulation is based on continuoustime approaches and incorporates two elaborate submodels that include a MILP formulation for raw material inventory and scheduling of nonsequential multipurpose batch plants with unlimited intermediate storage (UIS) policy. The key feature of this paper is to set up a raw material inventory model for batch scheduling problems. In case studies, the proposed formulation is used to solve a scheduling example of non-sequential multipurpose batch plants. This example is presented to prove that the proposed formulation is more reasonable than the formulation without raw material inventory constraints.