Materials receiving capacity and inventory management

This paper analyses the optimal level of materials receiving capacity for a manufacturer that receives deliveries from many suppliers. Inventory levels and inventory carrying costs depend on the frequency of deliveries and thus, on the materials receiving capacity. An analytic model that captures the tradeoff between inventory costs and materials receiving costs is presented and discussed. The receiving cost is modeled as increasing in discrete jumps of varying sizes whenever materials receiving resources are added. Practical issues in implementing the model are highlighted and methods to reduce the marginal materials receiving cost are discussed. The paper also discusses connections to the JIT approach for production environments where materials receiving is heavily automated.     

The Instruction set of Questionnaires can Affect the Structure of the Data: Application to Self-Rated State Anxiety

The present study tested the assumption that self-ratings, such as those used for measuring state anxiety, do not measure a one-dimensional transcendent entity but involve decisions based on a multi-dimensional judgment. Two groups of subjects were presented with a balanced nine-item state anxiety questionnaire. Each group received a different set of instructions (a standard set and an altered instruction set suggesting unidimensionality of the questions in the questionnaire). It was hypothesized that this change in instructions would impact the structure of the data. The impact of the instructions was detectable at the level of the observed correlation between the negative and positive composites, Cohen's (1988) q=–0.27$. A multigroup confirmatory factor analysis showed that positive and negative wording factors correlated more strongly when unidimensionality was suggested than when standard instructions were used, q=–0.54. Theoretical and practical implications are discussed.     

Assessing the Structural Robustness of Self-Rated Satisfaction With Life: A SEM Analysis

Structural invariance of self-rated satisfaction with life data was assessed using four data sets collected in earlier studies by using the Satisfaction With Life Scale. Three measurement models were compared to account for structural variability of the data. Strict structural invariance was rejected. Departure from the one-factor model was only found in data gathered using the items in successive order. When the items were scattered among other items, only quantitative variability was found. The findings did not support the view of a generalized one-factor model but suggested measurement artifacts. Qualitative structural variability impacted the scale reliability estimates. Although experimental replication of an ordering effect is warranted, this study suggests that scattering the items can be recommended in order to optimize the structural validity of this concept.     

Conditions for the successful integration of Human and Organizational Factors (HOF) in the nuclear safety analysis

This communication presents some elements which come from the experience feedback at CEA about the conditions for the successful integration of HOF in the nuclear safety analysis. To point out some of these conditions, one of the concepts proposed by Edgar Morin to describe the functioning of "complex" systems: the dialogical principle has been used. The idea is to look for some dialogical pairs. The elements of this kind of pair are both complementary and antagonist to one another. Three dialogical pairs are presented in this communication. The first two pairs are related to the organization of the HOF network and the last one is related to the methods which are used to analyse the working situations. The three pairs are: specialist - non-specialist actors of the network, centralized - distributed human resources in the network and microscopic - macroscopic levels of HOF methods to analyse the working situations. To continuously improve these three dialogical pairs, it is important to keep the differences which exist between the two elements of a pair and to find and maintain a balance between the two elements of the pairs.