We present two decomposition algorithms for single product deep-sea maritime inventory routing problems (MIRPs) that possess a core substructure common in many real-world applications. The problem involves routing vessels, each belonging to a particular vessel class, between loading and discharging ports, each belonging to a particular region. Our algorithms iteratively solve a MIRP by zooming ...

In a novel dual bed reactor Fischer-Tropsch synthesis was studied by using two diffrent cobalt catalysts. An alkali-promoted cobalt catalyst was used in the first bed of a fixed-bed reactor followed by a Rutenuim promoted cobalt catalyst in the second bed. The activity, product selectivity and accelerated deactivation of the system were assessed and compared with a conventional single bed r...

Abstract. In this paper, a production inventory model is developed for the business enterprise which consists of three wings. The first wing is for manufacturing new items, the second wing is for collecting the returned items, while third wing is for remanufacturing the returned item. In this model we consider the fact that the storage item is deteriorated during storage periods and salvage val...

I n this paper, we study a single-product periodic-review inventory system that faces random and price-dependent demand. The firm can purchase the product either from option contracts or from the spot market. Different option contracts are offered by a set of suppliers with a two-part fee structure: a unit reservation cost and a unit exercising cost. The spot market price is random and its real...

In this paper, we establish the convexity of important cost functions in a general class of multi-echelon inventory models. In particular, we first study an assembly system with a single finished product managed using an echelon order-up-to policy. We show that the shortage penalty cost over any horizon is jointly convex with respect to the base-stock levels and capacity levels. Our second resu...

This paper studied a continuous-time model of a production maintenance system in which a manufacturing firm produces a single product selling some and stocking the remaining. The problem of adaptive control of a production-maintenance system with unknown deterioration has been presented. Using Liapunov technique, the production rate and updating rule of deterioration rate are derived as non-lin...

Erratic demands have traditionally shown complexity in inventory management and forecasting. Several organisations, especially in multi-product manufacturing systems with intermittent demand high level of variability and uncertainty, assume suitable estimators are put in place to forecast demand. This forces them to pay attention to controlling the inventory of a system. The forecasted demand i...