Abstract Due to the main peculiarities of spare parts, i.e. intermittent demands, long procurement lead times and high downtime costs when parts are not available on time, it is often difficult find optimal inventory level. Recently, Additive Manufacturing (AM) has emerged as a promising technique improve management thanks ‘print demand’ approach. So far, however, impact AM been little consider...

inventory control is one of the most important issues in supply chain management. in this paper, a three-echelon production, distribution, inventory system composed of one producer, a set of wholesalers and retailers is considered. costumers' demands can be approximated by a normal distribution and the inventory policy is a kind of continuous review (r, q). in this paper, a model based on ...

this paper aims to evaluate inventory cost of a two-echelon serial supply chain system under vendor managed inventory program with stochastic demand, and examine the effect of environmental factors on the cost of overall system. for this purpose, we consider a two-echelon serial supply chain with a manufacturer and a retailer. under vendor managed inventory program, the decision on inventory le...

We derive approximations for the service levels of two-echelon inventory systems with lost sales and Poisson demand. Our method is simple and accurate for a very broad range of problem instances, including cases with both high and low service levels. In contrast, existing methods only perform well for limited problem settings, or under restrictive assumptions.

The multi-server queue with non-homogeneous Poisson arrivals and customer abandonment is a fundamental dynamic rate queueing model for large scale service systems such as call centers and hospitals. Scaling the arrival rates and number of servers arises naturally when a manager updates a staffing schedule in response to a forecast of increased customer demand. Mathematically, this type of scali...

Background & Aims of the Study: Worker’s behaviors, uncontrolled job stress, psycho- social factors and non-ergonomic principles, lead to risk of musculoskeletal disorders. This rsearch was done conducted to analyze relationship these factors in an auto-parts production company in Qom province, Iran in 2015. Materials and Methods: This study was a cross-sectional one condu...

Many firms face environments with long production lead times, great product variety, and uncertain, non-stationary demand. A challenge is how to plan production and inventories to provide competitive customer service at least cost. In this paper, we first describe an application at Teradyne in which we implemented an inventory hedge to protect against cyclic demand variability. Based on this ex...

As the plug-in hybrid electric vehicle (PHEV) is becoming a very significant component in residential loads, an accurate and valid model for the PHEV charging demand is the key for load forecast, demand respond, system planning and so forth. As a result, we propose a data driven queuing model for residential PHEV charging demand by performing data analytics on smart meter measurements. The data...

This paper explores an efficient Medium Access Control protocol for carrying data traffic via satellite. The Combined Free/Demand Assignment Multiple Access (CFDAMA) protocol combines free assignment of data slots with demand assignment, providing a minimum delay of one round trip time at low loads and the statistical multiplexing gains of demand assignment at high loads. The delay/utilisation ...