Geismar et al. [8] consider a similar problem with single machine production and a single vehicle to deliver a single
perishable product. The plant must satisfy all customer demands but the sequence of production and delivery are
flexible. Also, the customer does not have time requirements for delivery but the perishable product has a constant
lifetime so every order must be delivered before the lifetime expires. The objective is to find the minimum time span
to satisfy all customers’ orders. A two-phase heuristic method was proposed for this strongly NP-hard problem [8].