Concepts for Safety Stock Determination under Stochastic Demand and Different Types of Random Production Yield

We consider a manufacturer\u27s stochastic production/inventory problem under periodic review and present concepts for safety stock determination to cope with uncertainties that are caused by stochastic demand and different types of yield randomness. Order releases follow a linear control rule. Taking manufacturing lead times into account it turns out that safety stocks have to be considered that vary from period to period. We present an approach for calculating these dynamic safety stocks. Additionally, to support practical manageability we suggest two approaches for determining appropriate static safety stocks that are easier to apply

Concepts for Safety Stock Determination under Stochastic Demand and Different Types of Random Production Yield

We consider a manufacturer's stochastic production/inventory problem under periodic review and present concepts for safety stock determination to cope with uncertainties that are caused by stochastic demand and different types of yield randomness. Order releases follow a linear control rule. Taking manufacturing lead times into account it turns out that safety stocks have to be considered that vary from period to period. We present an approach for calculating these dynamic safety stocks. Additionally, to support practical manageability we suggest two approaches for determining appropriate static safety stocks that are easier to apply.stochastic demand, random yield, lot sizing, safety stocks

How Yield Process Misspecification Affects the Solution of Disassemble-to-order Problems

Random yields from production are often present in manufacturing systems and there are several ways that this can be modeled. In disassembly planning, the yield uncertainty in harvesting parts from cores can be modeled as either stochastically proportional or binomial, two of these alternatives. A statistical analysis of data from engine remanufacturing of a major car producer fails to provide conclusive evidence on which kind of yield randomness might prevail. In order to gain insight into the importance of this yield assumption, the impact of possible yield misspecification on the solution of the disassemble-to-order problem is investigated. Our results show that the penalty for misspecifying the yield method can be substantial, and provide insight on when the penalty would likely be problematic. The results also indicate that in the absence of conclusive information on which alternative should be chosen, presuming binomial yields generally leads to lower cost penalties and therefore preferable results

Vermeidung, Substitution und nachhaltige Kreislaufwirtschaft von Kunststoffen: das Projekt „reGIOcycle“ – 1. Teil Forschungsphase (2020–2023)

Kunststoffe haben die Welt erobert – sie sind ubiquitär! Produktion, Nutzung und Entsorgung von Kunststoffen sind jedoch mit erheblichem Ressourcenverbrauch, Vermüllung, Mikroplastik, Meeresverschmutzung und negativen Auswirkungen auf unsere Ökosysteme und Gesundheit verbunden. Um diese gesellschaftliche Herausforderung anzugehen, besteht auch für Kommunen Handlungsbedarf. Das Projekt reGIOcycle steht für Vermeidung, Substitution und nachhaltige Kreislaufwirtschaft von Kunststoffen auf der regionalen Ebene. Ziel war die Entwicklung und Erprobung eines realisierbaren Konzepts zur nachhaltigen Kreislaufwirtschaft, unter Mitwirkung verschiedener Akteure und Stakeholder aus Kommunen, Forschungseinrichtungen und lokal agierender Unternehmen. Vor diesem Hintergrund wurde mit reGIOcycle versucht, Ansätze und Potenziale für regionale Kunststoffkreisläufe in Stadt-Land-Beziehungen im Sinne der Vermeidung, Substitution mittels biobasierter Alternativen und einer nachhaltigen Kreislaufwirtschaft abzuleiten. In dem Band wird eine Rohstoffpotenzialanalyse dargestellt, auf deren Basis mögliche Ansatzpunkte in der Region Augsburg für eine optimierte Kreislaufwirtschaft und zur Substitution von Kunststoffprodukten diskutiert und Ideen dazu entwickelt wurden