One-way or reusable distribution items? Department or Operations Planning and Control . •• Working Paper Series CIiE-v&Y CIt IlBDSABLE DIS1.1UBDTIQR lTIIIS? ONE-WAY OR REUSABLE DISTRIBUTION ITEMS?

ABSTRACT For companies it becomes still more important to pay attention to the load carriers, containers and package materials, that they buy, lease or rent to distribute their products due to increasing expenses for disposing the above distribution items (DIs) after use and a changing public opinion in favor of the environment. The same holds for the DIs used by their suppliers. A concrete framework, based on the life-cycles of DIs, is presented to provide in a systematic way insight into the potential pro's and con's of one-way and reusable DIs. Attention is paid to the strategic, functional, technical, environmental, logistics, information, organisational and financial aspects related to the use of DIs. Special attention is paid to the specific consequences of using the two types of DIs for suppliers and purchasers. Suggestions for further research are given

On the operational logistic aspects of reuse.

For still more companies, it is or will become important to pay attention to the possibilities for reusing the products they produce and the items, like pallets and package materials, that they use for distributing their products or which are used by others for supplying their products to them. One important reason for the above is the growing concern for the natural environment, among others resulting in environmental laws which not only force companies to take back their products from their customers and the items used for the distribution of these products when these products or distribution items (DIs) are no longer desired by these customers, but also to take care of the environmentally friendly disposal of these products and Dis. However, due to the same reason, this disposal is becoming still more difficult and expensive (see e.g., Cairncross, 1990). Apart from being forced by law, companies feel forced to do the above because of competition and public opinion. But there are more reasons why it may be worthwhile for companies to consider reuse: there are products, components, materials and DIs that can be obtained cheaper or more quickly via reuse than via purchasing or producing anew

Herstellen van productie-uitval

Het herstellen van productie-uitval kan worden omschreven als het transformeren van tijdens of direct na productie afgekeurde exemplaren of batches van producten in goede exemplaren of batches voordat deze naar afnemers worden gedistribueer

Substitutie van resources voor het oplossen van tijdelijke problemen

Substitutie van resources, waaronder mensen, machines, gereedschappen, materialen, toeleveranciers en transporteurs, voor het oplossen van tijdelijke problemen met standaard gebruikte resources is de inzet van alternatieve resources om alsnog tijdig aan een vraag te kunnen voldoen

Condition-based maintenance for complex systems based on current component status and Bayesian updating of component reliability

\u3cp\u3eWe propose a new condition-based maintenance policy for complex systems, based on the status (working, defective) of all components within a system, as well as the reliability block diagram of the system. By means of the survival signature, a generalization of the system signature allowing for multiple component types, we obtain a predictive distribution for the system survival time, also known as residual life distribution, based on which of the system's components currently function or not, and the current age of the functioning components.The time to failure of the components of the system is modeled by a Weibull distribution with a fixed shape parameter. The scale parameter is iteratively updated in a Bayesian fashion using the current (censored and non-censored) component lifetimes. Each component type has a separate Weibull model that may also include test data.The cost-optimal moment of replacement for the system is obtained by minimizing the expected cost rate per unit of time. The unit cost rate is recalculated when components fail or at the end of every (very short) fixed inter-evaluation interval, leading to a dynamic maintenance policy, since the ageing of components and possible failures will change the cost-optimal moment of replacement in the course of time. Via numerical experiments, some insight into the performance of the policy is given.\u3c/p\u3

Optimal core acquisition and remanufacturing policies under uncertain core quality fractions

Cores acquired by a remanufacturer are typically highly variable in quality. Even if the expected fractions of the various quality levels are known, then the exact fractions when acquiring cores are still uncertain. Our model incorporates this uncertainty in determining optimal acquisition decisions by considering multiple quality classes and a multinomial quality distribution for an acquired lot. We derive optimal acquisition and remanufacturing policies for both deterministic and uncertain demand. For deterministic demand, we derive a simple closed-form expression for the total expected cost. In a numerical experiment, we highlight the effect of uncertainty in quality fractions on the optimal number of acquired cores and show that the cost error of ignoring uncertainty can be significant. For uncertain demand, we derive optimal newsboy-type solutions for the optimal remanufacture-up-to levels and an approximate expression for the total expected cost given the number of acquired cores. In a further numerical experiment, we explore the effects of demand uncertainty on the optimal acquisition and remanufacturing decisions, and on the total expected cost