In-house Production Research Articles

A mathematical model for the design of distributed layout by considering production planning and system reconfiguration over multiple time periods

In this paper, we develop a new mathematical model that integrates layout configuration and production planning in the design of dynamic distributed layouts. The model incorporates a number of important manufacturing attributes such as demand fluctuation, system reconfiguration, lot splitting, work load balancing, alternative routings, machine capability and tooling requirements. In addition, the model allows several cost elements to be optimized in an integrated manner. These costs are associated with material handling, machine relocation, setup, inventory carrying, in-house production and subcontracting needs. Numerical examples of different sizes are presented to illustrate the nature of the developed model and shed light on several managerial insights.

Radiology Teaching Files: an Assessment of Their Role and Desired Features Based on a National Survey.

A radiology teaching file (TF) is a system containing a collection of cases with teaching value. Given the wide variety of TF solutions available, we conducted a national survey to better understand the need for TFs, TF features desired by users and their current implementation. A 28-question survey was created which explored TF implementation, utilization, and preferences among respondents. The survey was emailed to residents and faculty throughout the USA, with a request for program coordinators to forward the survey to their departments. The survey was completed by 396 respondents from 115 different institutions. These respondents included 60% residents, 21% attendings (non-program directors), 12% program directors, 5% fellows, and 1% medical students. TFs were assigned to one of three categories: personal TFs, shared in-house TFs, and public TFs. Seventy-six percent of respondents kept a personal TF using a variety of media, and 67% used a shared in-house TF. Of the public TFs used, the most popular were those requiring paid subscriptions. The features respondents valued most provided efficient querying of cases, simulated basic PACS functionality, enabled self-directed learning, and facilitated case submissions. There is a trend toward utilizing electronic media for TFs. The media utilized should be understood and reviewed to ensure PHI is properly secured. Contemporary users demand a high degree of functionality from TF solutions, and use both in-house and commercial products to meet their needs.

In-house Production and Sourcing Competition under Demand Uncertainties

In this paper, we consider a supply chain where two buyers compete by investing in in-house capacity and outsourcing the remaining part of its production requirements to a common supplier to serve their individual markets with uncertain demand. The supplier has the option to sell capacity to these buyers and to an alternative market with random demand. We determine the buyers’ optimal sourcing and in-house production capacity decisions under such scenario.

Heuristic Supply Chain Optimization of Networked Maintenance Companies

This paper considers the problem of networked maintenance companies and the connected purchasing processes. Today's successful operation of companies views maintenance as a high priority to ensure maximum utilisation of resources. In this article, a mathematical model is first developed to formulate the problem of finding the optimal make-or-buy solution for complex spare part production. The model seeks the optimal proportion of in-house and outsourced productions, as well as the order quantity so as to minimize the total costs while taking into account order limits. Next, we demonstrate an enhanced harmony search algorithm dealing with multi-objective supply chain model to find the optimum make-or-buy solution of a given maintenance related supply chain problem. We also discuss the sensibility analysis of the heuristic optimisation method and propose optimal process parameters for a high convergence. Numerical results demonstrate how the proposed model supports the make-or-buy decision and helps to reduce the total costs while keeping high availability to fulfil maintenance tasks.

Managing the Newsvendor Modeled Product System with Random Capacity and Capacity-Dependent Price

We consider a newsvendor modeled product system, where the firm provides products to the market. The supply capacity of the product is random, so the firm receives either the amount of order quantity or the realized capacity, whichever is smaller. The market price is capacity dependent. We consider two types of production cost structures: the procurement case and the in-house production case. The firm pays for the received quantity in the former case and for the ordered quantity in the latter case. We obtain the optimal order quantities for both cases. Comparing with the traditional newsvendor model, we find that the optimal order quantity in both the procurement case and the in-house production case are no greater than that in the traditional newsvendor model with a fixed selling price. We also find that the optimal order quantity for the procurement case is greater than that for the in-house production case. Numerical study is conducted to investigate the sensitivity of the optimal solution versus the distribution of the random capacity/demand.

Evaluating the Impact of Boosting on-site Enzymes produced by Trichoderma reesei RUT C30 and Aspergillus saccharolyticus with Commercial Enzymes in lowering the use of Commercial Cellulases.

In-house production of cellulases from filamentous fungi is widely used, but their hydrolytic efficiency compared to commercial enzymes is limited. We studied the effect of supplementing in-house cellulases produced by Trichoderma reesei, RUT C30 and a novel strain, Aspergillus saccharolyticus with different types of commercial enzymes for the efficient hydrolysis of wet exploded loblolly pine. Cellic®Ctec 2, Cellic®Htec2 and Novozym 188 were used as the commercial base enzymes for supplementing the in-house produced enzymes. Compared to non- supplemented in-house enzymes preparation, commercial enzymes (Cellic®Ctec2) added in the same amount as FPU and CBU, resulted in 68% higher glucose yield using wet exploded loblolly pine (WELP) at a 20% DM concetration. The highest saccharifcation yield was achieved by supplementation of the in-house produced cellulases with Cellic®Htec2 compared to Cellic®Ctec2 and Novozym 188. Optimal glucose, xylose and mannose yields, 85%, 92% and 86%, respectively were achieved by using in-house enzymes (15 FPU/g cellulose) supplemented with commercial hemicellulase (7.5 FPU/g cellulose). These results showed that supplementing in-house enzymes with commercial enzymes can be advantageous and work for lowering the overall cost of enzymes in a biorefinery.

Camptothecin and its analogs reduce amyloid-β production and amyloid-β42-induced IL-1β production.

Compounds derived from natural products are becoming promising alternative drugs/tools in Alzheimer's disease (AD) therapeutics. From an in-house natural products library, seventeen hits were selected for their inhibitory effect on the production of amyloid-β (Aβ) with IC50 lower than 10 μM without causing obvious toxicity. Among these compounds, camptothecin (CPT) and its analogs showed inhibitory effects on amyloid-β 1-42 (Aβ42) with the IC50 value in the nanomolar range in HEKsw cells and SHSY5Ysw cells. Further studies showed that CPT and its analogs inhibited Aβ42 via a p53 dependent pathway. Meanwhile, CPT and its analogs could also inhibit Aβ42 induced IL-1β production in the THP-1 cells. Taken together, our results indicate that CPT and its analogs would be a promising therapeutic candidates for AD.

Positron range in PET imaging: non-conventional isotopes

In addition to conventional short-lived radionuclides, longer-lived isotopes are becoming increasingly important to positron emission tomography (PET). The longer half-life both allows for circumvention of the in-house production of radionuclides, and expands the spectrum of physiological processes amenable to PET imaging, including processes with prohibitively slow kinetics for investigation with short-lived radiotracers. However, many of these radionuclides emit ‘high-energy’ positrons and gamma rays which affect the spatial resolution and quantitative accuracy of PET images.The objective of the present work is to investigate the positron range distribution for some of these long-lived isotopes.Based on existing Monte Carlo simulations of positron interactions in water, the probability distribution of the line of response displacement have been empirically described by means of analytic displacement functions.Relevant distributions have been derived for the isotopes 22Na, 52Mn, 89Zr, 45Ti, 51Mn, 94mTc, 52mMn, 38K, 64Cu, 86Y, 124I, and 120I. It was found that the distribution functions previously found for a series of conventional isotopes (Jødal et al Phys. Med. Bio. 57 3931–43), were also applicable to these non-conventional isotopes, except that for 120I, 124I, 89Zr, 52Mn, and 64Cu, parameters in the formulae were less well predicted by mean positron energy alone.Both conventional and non-conventional range distributions can be described by relatively simple analytic expressions. The results will be applicable to image-reconstruction software to improve the resolution.

Coordinating the Scheduling of Subcontracted Operations: Centralization, Competition and First-Come-First-Served Processing

Subcontracting has become a prominent business practice across many industries. Subcontracting of industrial production is generally based on short-term need for additional processing capacity, and is oftentimes employed by manufacturers to process customer orders more quickly than using only in-house production. In this article we study a popular business model where multiple manufacturers, each capable of processing his entire workload in-house, have the option to subcontract some of their operations to a single third-party with a flexible resource. Each manufacturer can deliver customer orders only after his entire batch of jobs, processed in-house and at the third-party, is completed. The third-party facility is available to several manufacturers who compete for its use. Current business practice of First-Come-First-Served (FCFS) processing of the subcontracted workloads as well as the competitive Nash equilibrium schedules developed in earlier studies result in two types of inefficiencies; the third-party capacity is not maximally utilized, and the manufacturers incur decentralization cost. In this article we develop models to assess the value created by coordinating the manufacturers' subcontracting decisions by comparing two types of centralized control against FCFS and Nash equilibrium schedules. We present optimal and/or approximate algorithms to quantify the third-party under-utilization and the manufacturers' decentralization cost. We find that both inefficiencies are more severe with competition than they are when the third-party allocates capacity in a FCFS manner. However, without centralized control, a larger percentage of the players prefer Nash equilibrium schedules to FCFS schedules. We extend our analysis to incomplete information scenarios where manufacturers reveal limited demand information, and find that more information dramatically benefits the third-party and the manufacturers, however, the marginal benefits are decreasing.Finally, we discuss an extension wherein each manufacturer's objective takes into account asymmetries in subcontracting, in-house processing, and delay costs. Finally, we discuss an extension wherein each manufacturer’s objective takes into account asymmetries in subcontracting, in-house processing, and delay costs.

Enzymatic Hydrolysis of Sugarcane Bagasse Using Enzyme Extract and Whole Solid-state Fermentation Medium of Two Newly Isolated Strains of Aspergillus Oryzae

Enzymatic conversion of lignocellulosic biomass into fuels and chemicals will be a key technology in the future. However, in order to make this process economically feasible, it is necessary to improve the efficiency of enzyme production, since the cost of the enzymatic cocktails significantly influences the viability of the overall process. In this sense, the use of solid-state fermentation (SSF) is particularly advantageous for enzyme production. Here, a comparative study on the enzymatic hydrolysis of steam- exploded sugarcane bagasse (SESB) using enzymatic extract (EE) and whole solid-state fermentation medium (WM) of two newly isolated strains of Aspergillus oryzae (P6B2 and P27C3A) from the Amazon Rainforest was carried out. The biomass conversion using WM from A. oryzae P6B2 was more efficient when compared with the EE, while for A. oryzae P27C3A the conversion yields were similar. The WM from P27C3A supplemented with a low dosage of commercial enzyme resulted in a final conversion of 45% of the theoretical value. Furthermore, the combination of the enzymes from both strains, allowed up to 5 folds improvement in SESB conversion. These results showed that the in-house enzyme production by wild-typeoryzae strains cultivated under SSF can be very advantageous for the enzymatic hydrolysis of biomass and, thus, it can be considered as a potential biotechnological configuration for the production of biofuels.

Perspectives on food traceability: a systematic literature review

Purpose– This paper aims to increase our understanding of perspectives on food traceability in four supply chain risk management (SCRM) approaches to ensure food safety. The occurrence of food safety failures has led to increased attention on food traceability as a means of identifying the causes of deficiencies in supply chains.Design/methodology/approach– This paper presents a literature review and synthesizes the broader domain of food traceability by analyzing perspectives based on SCRM approaches. In all, 129 published papers were selected and evaluated using content analysis.Findings– A framework of SCRM approaches on food traceability is presented. Eight perspectives on food traceability are identified and grouped according to four SCRM approaches: food supply chain complexity and unique identification of goods (logistics management); transparency and interoperability (information management); in-house production and outsourcing (production management); and food quality and safety requirements and the monitoring of food characteristics (quality management).Research limitations/implications– The findings provide an in-depth understanding and research suggestions for the management of traceability to ensure food safety in food supply chains. Conclusions are drawn from secondary sources, thus excluding empirical evaluation.Practical implications– The implementation of food traceability can result in changes to existing management systems. This paper addresses the perspectives and management challenges that can influence the implication of food traceability to ensure food safety.Originality/value– Perspectives on food traceability according to SCRM approaches are presented. Food traceability is analyzed using the philosophy of scientific framework and suggestions for further research are offered.

LAT-1 based primary breast cancer detection by [99m]Tc-labeled DTPA-bis-methionine scintimammography: first results using indigenously developed single vial kit preparation.

To evaluate the diagnostic utility of a single vial ready to label with [99m]Tc kit preparation of DTPA-bis-methionine (DTPA-bis-MET) for the detection of primary breast cancer. The conjugate (DTPA-bis-MET) was synthesized by covalently conjugating two molecules of methionine to DTPA and formulated as a single vial ready to label with [99m]Tc lyophilized kit preparations. Thirty female patients (mean age=47.5±11.8 years; range=21-69 years) with radiological/clinical evidence of having primary breast carcinoma were subjected to [99m]Tc-methionine scintigraphy. The whole body (anterior and posterior) imaging was performed on all the patients at 5 minutes, 10 minutes, 1 hour, 2 hours, and 4 hours following an intravenous administration of 555-740 MBq radioactivity of [99m]Tc-methionine. In addition, scintimammography (static images; 256×256 matrix) at 1, 2, and 4 hours was also performed on all the patients. The resultant radiolabel, that is, [99m]Tc-DTPA-bis-MET, yielded high radiolabeling efficiency (>97.0%), radiochemical purity (166-296 MBq/μmol), and shelf life (>3 months). The radiotracer primarily gets excreted through the kidneys and localizes in the breast cancer lesions with high target-to-nontarget ratios. The mean±SD ratios on the scan-positive lesions acquired at 1, 2, and 4 hours postinjection were 3.6±0.48, 3.10±0.24, and 2.5±0.4, respectively. [99m]Tc-methionine scintimammography demonstrated an excellent sensitivity and positive predictive value of 96.0% each for the detection of primary breast cancer. Ready to label single vial kit formulations of DTPA-bis-MET can be easily synthesized as in-house production and conveniently used for the scintigraphic detection of breast cancer and other methionine-dependent tumors expressing the L-type amino acid transporter-1 receptor. The imaging technique thus could be a potential substitute for the conventional single-photon emission computed tomography (SPECT)-based tumor imaging agents, especially for tracers with nonspecific mitochondrial uptake. However, the diagnostic efficacy of [99m]Tc-methionine needs to be evaluated in a large cohort of patients through further multicentric trials.

Strategic outsourcing under technology spillovers

We study a supply chain in which an original equipment manufacturer (OEM) and a contract manufacturer (CM) compete in the finished goods market. The OEM can decide whether to outsource the intermediate good, a critical component for producing the finished good, from the CM or make in-house production. Technology transition improves the CM's production efficiency, and it can take two different forms: a direct technology transfer from the OEM to the CM or technology spillovers through outsourcing from the OEM to the CM. We document the possibility of strategic outsourcing, that is, the CM supplies the intermediate good to the OEM when she is less efficient than the OEM's in-house production. We find that technology spillovers can strengthen the incentive for strategic outsourcing. Furthermore, compared with direct technology transfers, outsourcing coupled with technology spillovers may generate more technology transition. Outsourcing is a particularly appropriate channel for implicit collusion when the OEM is not very efficient with the production of the intermediate good. Our results suggest that ex post competition on the finished goods can create room for ex ante collaboration and provide some implications on the OEM's outsourcing strategies when facing a competitive CM.© 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 501–514, 2014

Critical care medicine: a call for papers

Advances in medical sciences, technology, and the introduction of multidisciplinary patient care have placed critical care at the centre of health-care systems. Critical care is also a core element of The Lancet Respiratory Medicine’s scope. To this end, we will be publishing a special themed issue in critical care medicine at the end of 2014 to coincide with the 44th Critical Care Congress in Phoenix, Arizona, USA. We are therefore calling for submissions of high quality research articles in any area of critical care; we particularly welcome clinical trials. The Lancet group is dedicated to advancing respiratory and critical care medicine. The Lancet Respiratory Medicine, similary to The Lancet, thus has a rigorous fast-track process for original research, in which papers can be published online within 8 weeks from the date of submission. This process shows our belief that your research should be disseminated to the community in a timely manner. Additionally, we have no author fees for submission or plate charges thereby removing these potential barriers to publication. The Lancet group is a well known global brand with an innovative website that can highlight papers alongside author podcasts to make sure your papers reach a wide audience. All journals share a dedicated team of assistant editors who subedit papers after acceptance and thoroughly check data, fi gures, and tables. The journals also benefi t from having a team of in-house illustrators and production editors who can redraw fi gures and help to ensure that data are presented clearly. Please submit your paper through our e-submission system with reference to this call for papers in your covering letter. The deadline for submissions to be received is Sept 30, 2014. We look forward to reading your cutting edge research that could advance the fi eld of critical care medicine.

Cellulolytic and xylanolytic potential of high β-glucosidase-producing Trichoderma from decaying biomass.

Availability, cost, and efficiency of microbial enzymes for lignocellulose bioconversion are central to sustainable biomass ethanol technology. Fungi enriched from decaying biomass and surface soil mixture displayed an array of strong cellulolytic and xylanolytic activities. Strains SG2 and SG4 produced a promising array of cellulolytic and xylanolytic enzymes including β-glucosidase, usually low in cultures of Trichoderma species. Nucleotide sequence analysis of internal transcribed spacer 2 (ITS2) region of rRNA gene revealed that strains SG2 and SG4 are closely related to Trichoderma inhamatum, Trichoderma piluliferum, and Trichoderma aureoviride. Trichoderma sp. SG2 crude culture supernatant correspondingly displayed as much as 9.84 ± 1.12, 48.02 ± 2.53, and 30.10 ± 1.11unitsmL(-1) of cellulase, xylanase, and β-glucosidase in 30 min assay. Ten times dilution of culture supernatant of strain SG2 revealed thattotal activities were about 5.34, 8.45, and 2.05 orders of magnitude higher than observed in crude culture filtrate for cellulase, xylanase, and β-glucosidase, respectively, indicating that more enzymes are present to contact with substrates in biomass saccharification. In parallel experiments, Trichoderma species SG2 and SG4 produced more β-glucosidase than the industrial strain Trichoderma reesei RUT-C30. Results indicate that strains SG2 and SG4 have potential for low cost in-house production of primary lignocellulose-hydrolyzing enzymes for production of biomass saccharides and biofuel in the field.

A supply chain network game theory model with product differentiation, outsourcing of production and distribution, and quality and price competition

In this paper, we develop a supply chain network game theory model with product differentiation, possible outsourcing of production and distribution, and quality and price competition. The original firms compete with one another in terms of in-house quality levels and product flows, whereas the contractors, aiming at maximizing their own profits, engage in competition for the outsourced production and distribution in terms of prices that they charge and their quality levels. The solution of the model provides each original firm with its optimal in-house quality level as well as its optimal in-house and outsourced production and shipment quantities that minimize the total cost and the weighted cost of disrepute, associated with lower quality levels and the impact on a firm’s reputation. The governing equilibrium conditions of the model are formulated as a variational inequality problem. An algorithm, which provides a discrete-time adjustment process and tracks the evolution of the product flows, quality levels, and prices over time, is proposed and convergence results given. Numerical examples are provided to illustrate how such a supply chain network game theory model can be applied in practice. The model is relevant to products ranging from pharmaceuticals to fast fashion to high technology products.

Productivity and Elasticity Differential between Direct and Contract Workers in Indian Manufacturing Sector

Contractual employment is an increasing phenomenon in the in-house production while informal workers are available outside at low cost. The obvious question is: are they more productive? To enquire this, the present paper examines the elasticity and productivity differential between direct and contract workers using the three-digit industrial data for major Indian states during 1998–2006. A simple theoretical exercise suggests that when direct and contract workers are employed respectively for core and peripheral activities within in-house production, the use of contract workers could rise in response to technological change even if direct workers are more productive and decline. We assume that a firm can undertake core activities by subcontracting out in place of using direct employment. Our empirical results suggest that both elasticity and productivity of contract workers have been lower than those of direct workers, even when the share of contract workers is highly explained by the capital–output ratio. We argue that the contract workers are less productive because they do not receive direct benefits from the technological upgradation in core in-house activities. While the technological upgradation can replace direct workers and subcontracting, the contract workers to be used for peripheral in-house activities can increase along with in-house production.

Outsourcing decisions – the case of parallel production

Purpose – The purpose of this paper is to investigate an underexplored aspect of outsourcing involving a mixed strategy in which parallel production is continued in-house at the same time as outsourcing occurs. Design/methodology/approach – The study applied a multiple case study approach and drew on qualitative data collected through in-depth interviews with wood product manufacturing companies. Findings – The paper posits that there should be a variety of mixed strategies between the two governance forms of “make” or “buy.” In order to address how companies should consider the extent to which they outsource, the analysis was structured around two ends of a continuum: in-house dominance or outsourcing dominance. With an in-house-dominant strategy, outsourcing complements an organization's own production to optimize capacity utilization and outsource less cost-efficient production, or is used as a tool to learn how to outsource. With an outsourcing-dominant strategy, in-house production helps maintain complementary competencies and avoids lock-in risk. Research limitations/implications – This paper takes initial steps toward an exploration of different mixed strategies. Additional research is required to understand the costs of different mixed strategies compared with insourcing and outsourcing, and to study parallel production from a supplier viewpoint. Practical implications – This paper suggests that managers should think twice before rushing to a “me too” outsourcing strategy in which in-house capacities are completely closed. It is important to take a dynamic view of outsourcing that maintains a mixed strategy as an option, particularly in situations that involve an underdeveloped supplier market and/or as a way to develop resources over the long term. Originality/value – The concept of combining both “make” and “buy” is not new. However, little if any research has focussed explicitly on exploring the variety of different types of mixed strategies that exist on the continuum between insourcing and outsourcing.

Recent polarizing supermirror projects at the ILL

We present a status of recent projects involving the in-house production of neutron multilayer optics, mainly polarizing supermirrors, at the ILL. Our main "mass production" project is for the wide-solid angle analyzing benders for the future instrument WASP (Wide Angle Spin Echo). The current status of this project based on Co/Ti supermirrors, which spans several years, will be presented. Some parameters of polarizing supermirrors for cavity polarizers, mainly based on Fe/Si supermirrors and produced in the past few years for various ILL instruments, are also reported. Some supermirror samples produced in order to study depolarization effects are also mentioned.

The Effect of Varying Ingredient Composition on the Sensory and Nutritional Properties of a Pureed Meat and Vegetable

The objective of this research was to investigate the effects of ingredients and preparation methods on the sensory and nutritional properties of pureed turkey and carrots. Turkey samples varying in added liquid and muscle composition were developed. Seasoning application methods were also studied. Pureed carrots were formulated with no added thickener, added modified corn starch, rice cereal, or skim milk powder. Small changes in added liquid and seasoning application altered the perceived texture of the turkey. Pureed carrots with added modified corn starch were more slippery and firm than other samples. The addition of skim milk powder or rice cereal did not alter sensory properties but led to higher protein contents when compared to unthickened carrots. In-house formulations did not differ in sensory ratings of appearance and flavor when compared to commercial products but contained more carbohydrates. Modest changes in recipes for pureed products can improve sensory appeal and nutrient density; quality in-house products are feasible with only minor alterations.