Parameter Estimation for a Model With Both Imperfect Test and Repair

We describe estimation of the parameters of a manufacturing test and repair model using data available from that test. The model allows imperfect testing and imperfect repair. The principal problem that we address is of parameter identification, given insufficient data, that we address by making conservative assumptions on the property being measured and the associated parameter values. Several cases of commonly occurring test types, in the manufacture of electronic products, are considered

A New Test/Diagnosis/Rework Model for Use in Technical Cost Modeling of Electronic Systems Assembly

This paper presents a test/diagnosis/rework analysis model for use in technical cost modeling of electronic assemblies. The approach includes a model of test operations characterized by fault coverage, false positives, and defects introduced in test, in addition to rework and diagnosis operations that have variable success rates and their own defect introduction mechanisms. The model can accommodate an arbitrary number of rework attempts on any given assembly and can be used to optimize the fault coverage and rework investment during system tradeoff analyses. The model’s implementation allows all inputs to the model to be represented as probability distributions thereby accommodating inevitable uncertainties in input data present during tradeoff activities and uses Monte Carlo methods to determine model outputs

A Hierarchical Core Reference Ontology for New Technology Insertion Design in Long Life Cycle, Complex Mission Critical Systems

Organizations, including government, commercial and others, face numerous challenges in maintaining and upgrading long life-cycle, complex, mission critical systems. Maintaining and upgrading these systems requires the insertion and integration of new technology to avoid obsolescence of hardware software, and human skills, to improve performance, to maintain and improve security, and to extend useful life. This is particularly true of information technology (IT) intensive systems. The lack of a coherent body of knowledge to organize new technology insertion theory and practice is a significant contributor to this difficulty. This research organized the existing design, technology road mapping, obsolescence, and sustainability literature into an ontology of theory and application as the foundation for a technology design and technology insertion design hierarchical core reference ontology and laid the foundation for body of knowledge that better integrates the new technology insertion problem into the technology design architecture

Electronic Part Total Cost Of Ownership And Sourcing Decisions For Long Life Cycle Products

The manufacture and support of long life cycle products rely on the availability of suitable parts from competent suppliers which, over long periods of time, leaves parts susceptible to a number of possible long-term supply chain disruptions. Potential supply chain failures can be supplier-related (e.g., bankruptcy, changes in manufacturing process, non-compliance), parts-related (e.g., obsolescence, reliability, design changes), logistical (e.g., transportation mishaps, natural disasters, accidental occurrences) and political/legislative (e.g., trade regulations, embargo, national conflict). Solutions to mitigating the risk of supply chain failure include the strategic formulation of suitable part sourcing strategies. Sourcing strategies refer to the selection of a set of suppliers from which to purchase parts; sourcing strategies include sole, single, dual, second and multi-sourcing. Utilizing various sourcing strategies offer one way of offsetting or avoiding the risk of part unavailability (and its associated penalties) as well as possible benefits from competitive pricing. Although supply chain risks and sourcing strategies have been extensively studied for high-volume, short life cycle products, the applicability of existing work to long life cycle products is unknown. Existing methods used to study part sourcing decisions in high-volume consumer oriented applications are procurement-centric where cost tradeoffs on the part level focus on part pricing, negotiation practices and purchase volumes. These studies are commonplace for strategic part management for short life cycle products; however, conventional procurement approaches offer only a limited view for parts used in long life cycle products. Procurement-driven decision making provides little to no insight into the accumulation of life cycle cost (attributed to the adoption, use and support of the part), which can be significantly larger than procurement costs in long life cycle products. This dissertation defines the sourcing constraints imposed by the shortage of suppliers as a part becomes obsolete or is subject to other long-term supply chain disruptions. A life cycle approach is presented to compare the total cost of ownership of introducing and supporting a set of suppliers, for electronic parts in long life cycle products, against the benefit of reduced long-term supply chain disruption risk. The estimation of risk combines the likelihood or probability of long-term supply chain disruptions (throughout the part's procurement and support life within an OEM's product portfolio) with the consequence of the disruption (impact on the part's total cost of ownership) to determine the "expected cost" associated with a particular sourcing strategy. This dissertation focuses on comparing sourcing strategies used in long life cycle systems and provides application-specific insight into the cost benefits of sourcing strategies towards proactively mitigating DMSMS type part obsolescence

Analytical Methods for Performance Enhancement in Unreliable Multistage Manufacturing Systems with Imperfect Production

Ph.DDOCTOR OF PHILOSOPH

The impact of manufacturing offshore on technology development paths in the automotive and optoelectronics industries

Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2006.Includes bibliographical references (p. 202-209).This dissertation presents a two-case study of the impact of manufacturing offshore on the technology trajectory of the firm and the industry. It looks in particular at the automotive and optoelectronics industries. The dissertation uses an innovative combination of engineering modeling and qualitative research methods to provide insights into this question. The results suggest an important difference between the two cases. In the automotive case, the results do not show that manufacturing offshore changes the path of technology development. In the optoelectronics case, the results do suggest that manufacturing offshore may be changing the path of technology development. The cross-case analysis reveals several important similarities between the two cases: (1) the relative economic positions of the emerging technology and the prevailing design shift when production is transferred to developing East Asia; (2) while the emerging design is more cost-competitive in the U.S. production structure, the prevailing design is more cost-competitive in the developing East Asia production structure; (3) firms initially do not understand the implications of moving offshore for the competitiveness of their designs; (4) firms choose to produce the prevailing design offshore; and (5) although the firms' decisions to produce the prevailing design offshore are rational in a static model, they fail to take into account dynamic diseconomies - specifically, disincentives and disadvantages for innovations critical to long-term markets. In its conclusion, this dissertation suggests a generalizable framework for how technology may influence manufacturing location and how manufacturing location may influence technology. To develop a more representative framework will require additional case studies.by Erica R.H. Fuchs.Ph.D