Generalizations of the Optimal Final Inventory Model
The purpose of this note is to generalize the optimal final inventory model presented previously [Hadley, G., T. M. Whitin. 1961. An optimal final inventory model. Management Sci. 7(2) 179-183]. Two generalizations are made. First, the mean demand is allowed to vary with time so that dynamic situations may be studied. Secondly, the date of obsolescence is no longer required to be fixed but is instead allowed to be described by a probability distribution.
An Optimal Final Inventory Model
A model is developed which allows the determination of the optimal inventory level for an item at any time if no additional procurements are to be made. It is assumed that the item has a known date of obsolescence and that the demand is Poisson distributed with a fixed mean over the useful life of the tem. The model constitutes an extension of other life-of-type models in that both costs which are incurred at a fixed point in time liquidation losses and other costs which are a function of time carrying charges and stock-out costs are included. In many operational situations both of these types of costs are relevant.
The wellness behavior interaction model
A cognitive-behavioral model for conceptualizing wellness is proposed consisting of situational/antecedent variables, person variables, and consequence variables which, taken individually or together, may serve to describe and explain wellness behavior. The model also is interactional in the sense that different categories of variables or factors within a category may impact on each other in a multidirectional fashion. A selective review of research relating to each variable is provided to demonstrate the need for such a multidimensional conceptual scheme for wellness.