Publications

>This report describes the innovative modeling approach developed as a result of a 3-year Laboratory Directed Research and Development project. The overall goal of this project was to provide an effective suite of solvers for advanced production planning at facilities in the nuclear weapons complex (NWC). We focused our development activities on problems related to operations at the DOE's Pantex Plant. These types of scheduling problems appear in many contexts other than Pantex--both within the NWC (e.g., Neutron Generators) and in other commercial manufacturing settings. We successfully developed an innovative and effective solution strategy for these types of problems. We have tested this approach on actual data from Pantex, and from Org. 14000 (Neutron Generator production). This report focuses on the mathematical representation of the modeling approach and presents three representative studies using Pantex data. Results associated with the Neutron Generator facility will be published in a subsequent SAND report. The approach to task-based scheduling described here represents a significant addition to the literature for large-scale, realistic scheduling problems in a variety of production settings.

This paper describes formulations of the Evaluation Planning Module that have been developed since its inception. This module is one of the core algorithms in the Pantex Process Model, a computerized model to support production planning in a complex manufacturing system at the Pantex Plant, a US Department of Energy facility. Pantex is responsible for three major DOE programs -- nuclear weapons disposal, stockpile evaluation, and stockpile maintenance -- using shared facilities, technicians, and equipment. The model reflects the interactions of scheduling constraints, material flow constraints, and the availability of required technicians and facilities.

Effective use of resources that are shared among multiple products or processes is critical for agile manufacturing. This paper describes the development and implementation of a computerized model to support production planning in a complex manufacturing system at the Pantex Plant, a US Department of Energy facility. The model integrates two different production processes (nuclear weapon disposal and stockpile evaluation) that use common facilities and personnel at the plant. The two production processes are characteristic of flow-shop and job shop operations. The model reflects the interactions of scheduling constraints, material flow constraints, and the availability of required technicians and facilities. Operational results show significant productivity increases from use of the model.

A comprehensive environment, safety and health (ES&H) program allocates an extensive portion of its resources to information collection, management, and manipulation. Much of these resources are difficult to obtain and even more costly to ensure that they are sufficiently accurate; however, a system which collects information at the point which a process begins or a material enters a facility and maintains that information throughout its entire life-cycle is a more efficient approach to providing the data necessary to meet ES&H requirements. These data requirements for all the various groups within an ES&H program are associated with the properties and interactions among materials, personnel, facilities, hazards, waste and processes. Although each group is charged with addressing a particular aspect of these properties and interactions, the information they require can be aggregated into a coherent set of common data fields. It is these common data fields that the Cradle-to-Grave Tracking and Information System (CGTIS) is designed to satisfy. Research and development laboratories such as Sandia National Laboratories (SNL) are diverse in nature and, therefore, present a complex challenge to ES&H professionals. The remainder of this paper will describe the CGTIS as envisioned and implemented at SNL, define the requirements of a complete CGTIS, and review the current status of each system module at SNL.

This paper describes a formal process for selecting, from a diverse set of proposed waste minimization activities, those activities that provide the greatest benefit to DOE. A methodology for evaluating and prioritizing proposals was developed to illustrate how the selection process works and what types of data are required to characterize waste minimization activities. It is clearly impossible to remove all aspects of subjective judgment from the proposal selection process. With this important consideration in mind, the methodology presented is put forth to enhance, not replace, the traditional DOE decision-making process. With relatively minor refinements, this methodology can be immediately useful to DOE Environmental Restoration and Waste Management and Defense Program organizations in preparing, evaluating, and prioritizing waste minimization proposals. 7 refs., 1 tab., 2 figs.

The authors have developed and applied a methodology to evaluate and prioritize proposed waste minimization activities affecting Department of Energy (DOE) programs. The approach provides a systematic and defensible method for selecting a set of waste minimization proposals that maximizes the benefits to DOE while maintaining costs within a specified budget. The report discusses the development of a structured set of evaluation criteria to characterize waste minimization issues; techniques for documenting the anticipated and potential costs, risks, and benefits of waste minimization proposals; and a method of translating disparate data into a figure of merit for each proposal. A test case demonstration of this prioritization approach was applied to proposals currently being considered at two DOE weapons production facilities. Recommendations are provided for combining this approach with the existing DOE proposal selection process. 9 refs., 9 figs., 3 tabs.