A production/recycling model with stationary demand and return rates

A production–recycling system is investigated. A constant demand can be satisfied with production and recycling. The used items are bought back and then recycled. The not recycled products are disposed of. Two types of models are analyzed. The first model examines the EOQ related costs and minimizes the relevant costs. The second model generalizes the first model with introduction of the cost function with linear waste disposal, recycling, production and buyback costs. It is asked whether the pure (either production or recycling) or mixed strategies are optimal.