Measures of dynamism and urgency in logistics

van Lon, Rinde R. S.
Ferrante, Eliseo
Turgut, Ali Emre
Wenseleers, Tom
Vanden Berghe, Greet
Holvoet, Tom
Dynamism was originally defined as the proportion, of online versus offline orders in the literature on dynamic logistics. Such a definition however, loses meaning when considering purely dynamic problems where all customer requests arrive dynamically. Existing measures of dynamism are limited to either (1) measuring the proportion of online versus offline orders or (2) measuring urgency, a concept that is orthogonal to dynamism, instead. The present paper defines separate and independent formal definidons of dynamism and urgency applicable to purely dynamic problems. Using these formal definitions, instances of a dynamic logistic problem with varying levels of dynamism and urgency were constructed and several route scheduling algorithms were executed on these problem instances. Contrary to previous findings, the results indicate that dynamism is positively correlated with route quality; urgency, however, is negatively correlated with route quality. The paper contributes the theory that dynamism and urgency are two distinct concepts that deserve to be treated separately.


Approximate queueing models for capacitated multi-stage inventory systems under base-stock control
Avşar, Zeynep Müge (Elsevier BV, 2014-07-01)
A queueing analysis is presented for base-stock controlled multi-stage production-inventory systems with capacity constraints. The exact queueing model is approximated by replacing some state-dependent conditional probabilities (that are used to express the transition rates) by constants. Two recursive algorithms (each with several variants) are developed for analysis of the steady-state performance. It is analytically shown that one of these algorithms is equivalent to the existing approximations given in ...
KIRCA, O; KOKTEN, M (Elsevier BV, 1994-06-09)
In this paper a framework for a new heuristic approach for solving the single level multi-item capacitated dynamic lot sizing problem is presented. The approach uses an iterative item-by-item strategy for generating solutions to the problem. In each iteration a set of items are scheduled over the planning horizon and the procedure terminates when all items are scheduled. An algorithm that implements this approach is developed in which in each iteration a single item is selected and scheduled over the planni...
A conic quadratic formulation for a class of convex congestion functions in network flow problems
Gürel, Sinan (Elsevier BV, 2011-06-01)
In this paper we consider a multicommodity network flow problem with flow routing and discrete capacity expansion decisions. The problem involves trading off congestion and capacity assignment (or expansion) costs. In particular, we consider congestion costs involving convex, increasing power functions of flows on the arcs. We first observe that under certain conditions the congestion cost can be formulated as a convex function of the capacity level and the flow. Then, we show that the problem can be effici...
Enhanced adjacent extreme-point search and tabu search for the minimum concave-cost uncapacitated transshipment problem
Bazlamaçcı, Cüneyt Fehmi (Informa UK Limited, 1996-09-01)
Practicable methods for optimising concave-cast, uncapacitated transshipment networks are non exact. In this paper, one such effective method, that of adjacent extreme point search, is further developed to enhance its overall computational efficiency. The enhanced search algorithm is then imbedded in a tabu search scheme which proved capable of finding better solutions, by a wide margin in some instances. Another tabu search scheme, somewhat inferior in terms of solution quality but computationally more eff...
Multiobjective traveling salesperson problem on Halin graphs
Ozpeynirci, Ozgur; Köksalan, Mustafa Murat (Elsevier BV, 2009-07-01)
In this paper, we study traveling salesperson (TSP) and bottleneck traveling salesperson (BTSP) problems on special graphs called Halin graphs. Although both problems are NP-Hard on general graphs, they are polynomially solvable on Halin graphs. We address the multiobjective versions of these problems. We show computational complexities of finding a single nondominated point as well as finding all nondominated points for different objective function combinations. We develop algorithms for the polynomially s...
Citation Formats
R. R. S. van Lon, E. Ferrante, A. E. Turgut, T. Wenseleers, G. Vanden Berghe, and T. Holvoet, “Measures of dynamism and urgency in logistics,” EUROPEAN JOURNAL OF OPERATIONAL RESEARCH, pp. 614–624, 2016, Accessed: 00, 2020. [Online]. Available: