1.79-Approximation Algorithms for Continuous Review Single-Sourcing Lost-Sales and Dual-Sourcing Inventory Models

Stochastic inventory systems with lead times are often challenging to optimize, including single-sourcing lost-sales and dual-sourcing systems. Recent numerical results suggest that capped policies demonstrate superior performance over existing heuristics. However, the superior performance lacks a theoretical foundation. In “1.79-Approximation Algorithms for Continuous Review Single-Sourcing Lost-Sales and Dual-Sourcing Inventory Models,” the author provides a theoretical foundation for this phenomenon in two classical inventory models. First, in a continuous review lost-sales model with lead times and Poisson demand, he proves that a capped base-stock policy has a worst-case performance guarantee of 1.79 by conducting an asymptotic analysis under a large penalty cost and lead time. Second, in a more complex continuous review dual-sourcing model with general lead times and Poisson demand, he proves that a similar capped dual-index policy has a worst-case performance guarantee of 1.79 under large lead time and ordering cost differences. The results provide a deeper understanding of the superior numerical performance of capped policies and present a new approach to proving worst-case performance guarantees of simple policies in hard inventory problems.

CHANGE OF REGISTRATION PARADIGM AND HIS INFLUENCE ON PROSPECTS OF FORMING OF MODEL OF ACCOUNT OF ACTIVITY OF NONCOMMERCIAL COMMUNAL ENTERPRISES – ESTABLISHMENTS OF HEALTH PROTECTION IN THE CONDITIONS OF GLOBALIZATION

In a publication the specific of functioning of noncommercial enterprises is reflected in the field of a health protection and the necessity of construction of registration model is well-proven that takes into account the specific of activity and answers as to the requirements of current legislation in the field of an account so to the requirements of department registration regulations that is worked out by National service of health of Ukraine (NSHU). For the aim of research finding out of problem aspects and determination of prospects of their overcoming is put at forming of model of account of activity of noncommercial communal enterprises – establishments of health protection taking into account features and their operating conditions in the conditions of change of registration paradigm (global economic environment, specific of forming of financial results). In modern operating of sphere of health protection conditions consider a necessity to work out the effective model of financial account taking into account the specific of activity of noncommercial enterprises in the field of a health protection. To the features of: considerable volumes of single-sourcing his influence on forming of financial results; having a special purpose orientation of activity not on a financial result, but on providing of terms of grant of quality services in the field of a health protection; functioning of establishments in global environment. Accordingly consider expedient direction of further researches of ground of going near development of format of the department accounting for small noncommercial communal enterprises taking into account the specific of sphere of health protection and in accordance with operating national registration standards.

Improving effectiveness of spare parts supply by additive manufacturing as dual sourcing option

The low-volume spare parts business is often identified as a potential beneficiary of additive manufacturing (AM) technologies. Currently, high AM unit costs or low AM part reliabilities deem the application of AM economical inferior to conventional manufacturing (CM) methods in most cases. In this paper, we investigate the potential to overcome these deficiencies by combining AM and CM methods. For that purpose, we develop an approach that is tailored toward the unique characteristics of dual sourcing with two production methods. Opposed to the traditional dual sourcing literature, we consider the different failure behavior of parts produced by AM and CM methods. Using numerical experiments and a case study in the aviation industry, we explore under which conditions dual sourcing with AM performs best. Single sourcing with AM methods typically leads to higher purchasing and maintenance costs while single sourcing with CM methods increases backorder and holding costs. Savings of more than 30% compared to the best single sourcing option are possible even if the reliability or unit costs of a part sourced with AM are three times worse than for a CM part. In conclusion, dual sourcing methods may play an important role to exploit the benefits of AM methods while avoiding its drawbacks in the low-volume spare parts business.

Syntax-From-Doc

Producing syntax highlighting, code completion, and context-aware code documentation in IDEs is hard. It is especially hard at SAS where the age and complexity of the SAS programming language begets quirks and edge cases. To support the features expected in modern IDEs, SAS has historically relied on syntax information produced in an unscalable, opaque manual process. This article presents a case study of the multi-year project to replace this legacy process with a "syntax-from-doc" REST service that stores and serves syntax information as JSON objects that are extracted from SAS XML documentation. The goal of the project is to produce a scalable, continually updated single-sourcing process by which all SAS syntax information can be made uniform and available across our myriad products and services. Though not without bumps and bruises to show for the stumbles along the way, this project serves as an interesting example of leveraging modern continuous integration/continuous delivery tooling, multiple markup languages, and a diverse technology stack to solve a hard problem.

Strategic sourcing under recall loss sharing and product quality investment

Product recall has been a widespread practical operation risk in the production outsourcing. To remit even avoid product recall risk, this paper considers a two-echelon supply chain where the original equipment manufacturer (OEM) orders a critical component from one or two contract manufacturers (CMs) and uses it to produce finished product with potential quality defect. The CMs can decide investment level to reduce defect possibility and share recall loss with the OEM once product recall is implemented. When the recall loss sharing rate is fixed, the OEM may adopt the single sourcing strategy or the dual sourcing strategy which depends on the recall loss sharing rate. Moreover, if the sharing rate is relatively small, the single sourcing strategy is an optimal choice for the OEM. However, when the recall loss sharing rate is determined by the OEM, she prefers to adopt the dual sourcing strategy. Meanwhile, an increase of the recall loss sharing rate may not force the CM to improve product quality. By the numerical analysis, if the marginal recall loss is large or the wholesale price is relatively small, the OEM and the CMs can reach a win-win scenario. Finally, we examine an extension in which the CMs have pricing ability on wholesale price, and the result shows that the OEM can not obtain a cost-reduction benefit under the dual sourcing strategy.