This paper models supply chain (SC) uncertainties by fuzzy sets and develops a possibilistic SC configuration model for new products with unreliable or unavailable SC statistical data. The supply chain is modeled as a network of stages. Each stage may have one or more options characterized by the cost and lead-time required to fulfill required functions and may hold safety stock to prevent an i...

This paper proposes a reliability-based economic model predictive control (MPC) strategy for the management of generalised flow-based networks, integrating some ideas on network service reliability, dynamic safety stock planning, and degradation of equipment health. The proposed strategy is based on a single-layer economic optimisation problem with dynamic constraints, which includes two enhanc...

This paper is based on observations that competing retailers have the option of either agreeing in advance to transship excess inventory to each other or seeing unsatisfied customers switch to the competitor for a substitute. A transshipment game and a substitution game between competing retailers is studied. After establishing the existence and uniqueness of a pure-strategy Nash Equilibrium in...

In this note we consider a fluid flow, single part-type, single unreliable machine production system with a bounded backlog/inventory space. We prove that, as in the unbounded case, the problem of minimizing an infinite horizon average demand loss/backlog/surplus cost is solved by a hedging point policy. An implicit equation is given, whose structure easily allows to numerically evaluate the op...

The purpose of this paper is to validate and test the adequacy of an analytical expression to calculate proper safety stock levels using simulation techniques. The model refers to a periodic review system and a lot-4-lot replenishment policy, with randomness in forecast errors and in order fulfillment. The simulation model is formulated in a spreadsheet environment using MS Excel and @Risk. The...

We perform a structural estimation of the preference parameters in a buffer-stock consumption model augmented with temptation disutility. We adopt a two-stage Method of Simulated Moments methodology to match our simulated moments with those observed in the US Survey of Consumer Finances. To identify the parameters we use liquid and quasi-liquid (retirement) wealth holdings at different ages as ...

Simulation tools have been used to construct a virtual work/process environment for the purpose of process analyses. The construct of a simulation model uses the processes, resources, process flow, entities etc; coupled together by statistical relationships. Simulation models developed for planning and design are often aggregated models using statistical distributions to model stochastic nature...

Stock control is the most important aspect in an inventory system. It determines the safety stock in order to ensure that products are readily available when the customers require them. The decision makers in organizations tend to rely on software solution in obtaining stock control solutions since they have to manage a massive number of Stock Keeping Units (SKUs). However, managers intervene i...

This paper studies a two-echelon supply chain with stochastic and discrete consumer demand, batch order quantities, periodic inventory review, and deterministic transportation times. Reorder point policies manage inventories at every location. Average inventory, backorders and fill rates are evaluated exactly for each location. Safety stock is evaluated exactly at the lower echelon and a good a...

This paper concerns policy synthesis in large queuing networks. The results provide answers to the following questions: (i) It is well-known that an understanding of variability is important in the determination of safety stocks to prevent unwanted idleness. Is this the only use of high-order statistical information in policy synthesis? (ii) Will a translation of an optimal policy for the deter...