Optimization of facility location and reallocation in an industrial plant through a multi-annual framework accounting for economic and safety issues

• A multi-objective optimization approach for facility siting is proposed.
• Economic and safety aspects are considered simultaneously.
• A multi-period framework was incorporated.
• The domino effect was considered.
• Results show significant advantages obtained with the proposed approach.

The industrial layout traditionally has been addressed accounting for the facilities distribution and installation since the first day of operation of the plant; this is, without considering future expansions that involve additional facilities in the future operation years. This way, this paper proposes a mathematical programming formulation for the optimal facility sitting and reallocation in an industry accounting for future expansions and involving simultaneously economic and safety objectives. The proposed formulation is based on a multi-annual framework and this corresponds to a multi-objective mixed integer linear programming problem. The proposed optimization approach was applied to a case study for the facility sitting (office buildings and control rooms) in an ethylene oxide plant. The economic objective function involves the minimization of the total annual cost accounting for the value of the money through the time and the safety objective function involves the minimization for the accumulated risk over the operation time. Results show the applicability of the proposed approach.