Optimal supply planning in MRP environments for assembly systems with random component procurement times

Abstract

This paper examines supply planning in an MRP environment for assembly systems under lead time uncertainties. Indeed, inventory control in a supply chain is crucial for companies who wish to satisfy their customer demands on time as well as controlling costs. A common approach is to use the MRP techniques. However, these techniques are based on the supposition that lead times are known. In an actual supply chain the lead times are often random variables. Therefore, we develop an efficient exact model to aid in MRP parameterization under lead time uncertainties, more precisely to calculate planned lead times when the component procurement times are random. The aim is to find the values of planned lead times which minimize the sum of the average component holding cost and the average backlogging cost. The developed approach is based on a mathematical model of this problem with discrete decision variables and a branch and bound algorithm.

Supplier Replacement Model in a One-Level Assembly System under Lead-Time Uncertainty

“…However, serious weaknesses in the approach were that it is only valid if all component procurement lead times follow the same probability distribution and if all components have the same unit inventory holding cost. The optimization approach was generalized in [3] to consider procurement lead times that are independent, but not necessarily identically distributed in order to minimize the expected total cost. In continuation of this work, various approaches [36,[39][40][41][42] have attempted to extend this model to study other replenishment policies (L4L, POQ, EOQ, etc.)…”

“…In this paper, we extend the model proposed in [3] in order to investigate an OLAS under lead-time uncertainty and to examine the benefit of paying suppliers an additional purchase cost (APC) in order to reduce the costs of component lead-time uncertainty. In [3], a one-level assembly system was considered with several suppliers and random supplier lead times. The authors optimized planned lead-times for a fixed set of selected suppliers, taking into account the statistics on the real lead times.…”

“…The proposed model is an extension of the model in [3] but with completely new and challenging settings, specifically we are adding purchasing cost depending on the supplier reliability. This opens the possibility of finding solutions to as yet unsolved problems.…”

Supply chain dynamics, control and disruption management

“…For further reading on application of classic control theory to logistics and supply chain management, we refer to the study by Ortega and Lin (2004). Louly, Dolgui, and Hnaien (2008) addressed uncertainty in lead time and developed an approach to optimal supply planning in MRP environments for assembly systems with random component procurement times. Scholz-Reiter et al (2010) use stability analysis with regard to autonomously controlled production networks.…”

A Conceptual Model for Integrating Transport Planning: MRP IV

“…However, the premise of a completely deterministic scenario does not match the reality of a manufacturing environment. The literature reports different approaches to consider uncertainty in MRP systems, such as simulation [11], [12], stochastic inventory control [13], fuzzy logic [14], fuzzy mathematical programming [15][16][17][18], fuzzy programming with resources based on the credibility theory [19] and MRP parameterization [20][21][22], among others. Other approaches to consider uncertainty in MRP systems can be found in several reviews [23][24][25].…”