Economic impact of large public programs: The NASA experience

The economic impact of NASA programs on weather forecasting and the computer and semiconductor industries is discussed. Contributions to the advancement of the science of astronomy are also considered

Infrastructure dynamics: A selected bibliography

The term infrastructure is used to denote the set of life support and public service systems which is necessary for the development of growth of human settlements. Included are some basic references in the field of dynamic simulation, as well as a number of relevant applications in the area of infrastructure planning. The intent is to enable the student or researcher to quickly identify such applications to the extent necessary for initiating further work in the field

Comparison of a linear programming formulation of a production smoothing model and a combined linear and quadratic model

Two existing production smoothing and inventory control models have been compared. One is a linear programming model and the other model combines a linear inventory and manpower adjustment rule with a quadratic production cost function

Combined make-to-order and make-to-stock in a food production system

The research into multi-product production/inventory control systems has mainly assumed one of the two strategies: Make-to-Order (MTO) or Make-to-Stock (MTS). In practice, however, many companies cater to an increasing variety of products with varying logistical demands (e.g. short due dates, specific products) and production characteristics (e.g. capacity usage, setup) to different market segments and so they are moving to more MTO-production. As a consequence they operate under a hybrid MTO-MTS strategy. Important issues arising out of such situations are, for example, which products should be manufactured to stock and which ones on order and, how to allocate capacity among various MTO-MTS products. This paper presents the state-of-the-art literature review of the combined MTO-MTS production situations. A variety of production management issues in the context of food processing companies, where combined MTO-MTS production is quite common, are discussed in details. The authors propose a comprehensive hierarchical planning framework that covers the important production management decisions to serve as a starting point for evaluation and further research on the planning system for MTO-MTS situations.

Application of Enlisted Force Retention Levels and Career Field Stability

The Air Force’s success is influenced by the manpower it has. The end-strength is Congressionally mandated. Predicting personnel retention is critical to the operations of the military. Over 10 years ago, the Air Force produced enlisted career field sustainment lines based on manning. If a career field was over manned the authorizations were decreased, likewise if a career field was under manned the authorizations were increased. The constant fluctuation of manning caused bathtubs to be created and requirements to go unfilled. Currently, the Air Force produces enlisted career field sustainment lines based on the 5-year historical retention rates. This method produced a more steady state approach, as well as providing a means to adjust the line for other policy actions such as retraining in/out. The need to have a statistically based approach is essential for explaining and defending the creation of the sustainment lines. Many decisions that affect the methods selected for maintaining end-strength are based off the sustainment lines. Data from 2006-2015 was utilized in this research. Logistic regression was used to determine if any significant variables existed, however logistic regression did not provide enough insight into the behavior of the data to be utilized. A survival analysis approach, using retention data, provides a statistically sound methodology to the creation of the sustainment lines. This study produces sustainment lines based on the survival functions for each enlisted career field. It also analyzes the potential of grouping the years of service to manage the career and analyzes retention based on gender and on marital status

Shuttle Ground Operations Efficiencies/Technologies (SGOE/T) study. Volume 2: Ground Operations evaluation

The Ground Operations Evaluation describes the breath and depth of the various study elements selected as a result of an operational analysis conducted during the early part of the study. Analysis techniques used for the evaluation are described in detail. Elements selected for further evaluation are identified; the results of the analysis documented; and a follow-on course of action recommended. The background and rationale for developing recommendations for the current Shuttle or for future programs is presented