Periodic Review, Push Inventory Policies for Remanufacturing

Sustainability has become a major issue in most economies, causing many leading companies to focus on product recovery and reverse logistics. This research is focused on product recovery, and in particular on production control and inventory management in the remanufacturing context. We study a remanufacturing facility that receives a stream of returned products according to a Poisson process. Demand is uncertain and also follows a Poisson process. The decision problems for the remanufacturing facility are when to release returned products to the remanufacturing line and how many new products to manufacture. We assume that remanufactured products are as good as new. In this paper, we employ a "push" policy that combines these two decisions. It is well known that the optimal policy parameters are difficult to find analytically; therefore, we develop several heuristics based on traditional inventory models. We also investigate the performance of the system as a function of return rates, backorder costs and manufacturing and remanufacturing lead times; and we develop approximate lower and upper bounds on the optimal solution. We illustrate and explain some counter-intuitive results and we test the performance of the heuristics on a set of sample problems. We find that the average error of the heuristics is quite low.inventory;reverse logistics;remanufacturing;environment;heuristics

Integrating Closed-loop Supply Chains and Spare Parts Management at IBM

Ever more companies are recognizing the benefits of closed-loop supplychains that integrate product returns into business operations. IBMhas been among the pioneers seeking to unlock the value dormant inthese resources. We report on a project exploiting product returns asa source of spare parts. Key decisions include the choice of recoveryopportunities to use, the channel design, and the coordination ofalternative supply sources. We developed an analytic inventory controlmodel and a simulation model to address these issues. Our results showthat procurement cost savings largely outweigh reverse logistics costsand that information management is key to an efficient solution. Ourrecommendations provide a basis for significantly expanding the usageof the novel parts supply source, which allows for cutting procurementcosts.supply chain management;reverse logistics;product recovery;inventory management;service management

Building an IT Taxonomy with Co-occurrence Analysis, Hierarchical Clustering, and Multidimensional Scaling

Different information technologies (ITs) are related in complex ways. How can the relationships among a large number of ITs be described and analyzed in a representative, dynamic, and scalable way? In this study, we employed co-occurrence analysis to explore the relationships among 50 information technologies discussed in six magazines over ten years (1998-2007). Using hierarchical clustering and multidimensional scaling, we have found that the similarities of the technologies can be depicted in hierarchies and two-dimensional plots, and that similar technologies can be classified into meaningful categories. The results imply reasonable validity of our approach for understanding technology relationships and building an IT taxonomy. The methodology that we offer not only helps IT practitioners and researchers make sense of numerous technologies in the iField but also bridges two related but thus far largely separate research streams in iSchools - information management and IT management

Periodic Review, Push Inventory Policies for Remanufacturing

Sustainability has become a major issue in most economies, causing many leading companies to focus on product recovery and reverse logistics. This research is focused on product recovery, and in particular on production control and inventory management in the remanufacturing context. We study a remanufacturing facility that receives a stream of returned products according to a Poisson process. Demand is uncertain and also follows a Poisson process. The decision problems for the remanufacturing facility are when to release returned products to the remanufacturing line and how many new products to manufacture. We assume that remanufactured products are as good as new. In this paper, we employ a "push" policy that combines these two decisions. It is well known that the optimal policy parameters are difficult to find analytically; therefore, we develop several heuristics based on traditional inventory models. We also investigate the performance of the system as a function of return rates, backorder costs and manufacturing and remanufacturing lead times; and we develop approximate lower and upper bounds on the optimal solution. We illustrate and explain some counter-intuitive results and we test the performance of the heuristics on a set of sample problems. We find that the average error of the heuristics is quite low

Determinants of health, health behaviours and demographic profile of patients attending an Australian university student-led osteopathy clinic.

BackgroundProfiles of health professions practice can inform pre-professional education, provide evidence to assist with interprofessional practice, and inform policy development. An understanding of the profile of patients seeking osteopathy care is emerging. Current research suggests that musculoskeletal presentations predominate with approximately one-third of patients presenting with co-morbid diseases. There is little data on these presentations in Australian osteopathy practice. This study aimed to describe the patient demographics, clinical presentations, health behaviours and determinants of health, including health literacy, of those attending for care at an Australian student-led osteopathy clinic.MethodsA convenience sample design was utilised where consecutive patients presenting for their initial consultation were invited to complete a health information questionnaire during 2016-2017. The questionnaire explored a range of health behaviours and the patient's health status. Data from the clinical records were also extracted to establish the presenting complaint, duration of the complaint and pertinent demographics. Descriptive statistics were generated for each variable.ResultsData were available for 1617 patients presenting for their initial consultation. The mean age of patients was 33.7 (±13.1) years with 55% (n = 887) identifying as female. Acute presentations predominated (n = 840, 52%), with presentations affecting the spine being the most common (57.8%). Most patients rated their health status as good to very good (75%). Approximately 7.5% of patients were identified as having low health literacy and 55.9% were currently suffering from one or more co-morbid presentations.ConclusionsThe demographic profile and presenting complaints of patients presenting to a student-led osteopathy clinic are largely consistent with other Australian private practice profiles. The current work also identified co-morbid presentations, and positive and negative health behaviours. Osteopaths may play a role in the management of, or referral for, these presentations where health behaviours require change, or management of co-morbid conditions is beyond the scope of practice. The increasing volume of patient profile literature globally suggests that osteopaths can play a substantial role in the management of musculoskeletal complaints. Further, osteopathy may play a role in screening determinants of health, and engage in multidisciplinary care to ensure those patients with co-morbid conditions or adverse health behaviours are managed appropriately

Integrating Closed-loop Supply Chains and Spare Parts Management at IBM

Ever more companies are recognizing the benefits of closed-loop supply chains that integrate product returns into business operations. IBM has been among the pioneers seeking to unlock the value dormant in these resources. We report on a project exploiting product returns as a source of spare parts. Key decisions include the choice of recovery opportunities to use, the channel design, and the coordination of alternative supply sources. We developed an analytic inventory control model and a simulation model to address these issues. Our results show that procurement cost savings largely outweigh reverse logistics costs and that information management is key to an efficient solution. Our recommendations provide a basis for significantly expanding the usage of the novel parts supply source, which allows for cutting procurement costs

Can favourable psychosocial working conditions in midlife moderate the risk of work exit for chronically ill workers? A 20-year follow-up of the Whitehall II study

OBJECTIVES: To investigate if favourable psychosocial working conditions can reduce the risk of work exit and specifically for workers with chronic disease. METHODS: Men and women (32%) aged 35-55, working and having no chronic disease at baseline of the Whitehall II study of London-based civil servants were selected (n=9040). We observed participants' exit from work through retirement, health-related exit and unemployment, new diagnosis of chronic disease (ie, coronary heart disease, diabetes, stroke and cancer) and their psychosocial working conditions in midlife. Using cause-specific Cox models, we examined the association of chronic disease and favourable psychosocial working conditions and their interaction, with the three types of work exit. We adjusted for gender, occupational grade, educational level, remaining in civil service, spouse's employment status and mental health. RESULTS: Chronic disease significantly increased the risk of any type of work exit (HR 1.27) and specifically the risk of health-related exit (HR 2.42). High skill discretion in midlife reduced the risk of any type of work exit (HR 0.90), retirement (HR 0.91) and health-related exit (HR 0.68). High work social support in midlife decreased the risk of health-related exit (HR 0.79) and unemployment (HR 0.71). Favourable psychosocial working conditions in midlife did not attenuate the association between chronic disease and work exit significantly. CONCLUSIONS: The chronically ill have increased risks of work exit, especially through health-related exit routes. Chronic disease is an obstacle to extended working lives. Favourable working conditions directly relate to reduced risks of work exit

Reverse Logistics – Capturing Value in the Extended Supply Chain

Product flows in today’s supply chains do not end once they have reached the customer. Many products lead a second and even third or fourth life after having accomplished their original task at their first customer. Consequently, a product may generate revenues multiple times, rather than a single time. Capturing this value requires a broadening of the supply chain perspective to include new processes, known as ‘reverse logistics’, as well as multiple interrelated usage cycles, linked by specific market interfaces. Coordinating the successive product uses is key to maximizing the value generated. In this chapter, we review the field of reverse logistics. We discuss its opportunities and its challenges and indicate potential ways for companies to master them. We highlight what makes reverse logistics different from ‘conventional’ supply chain processes, but also point out analogies, and explain how both views can be integrated into an extended supply chain concept. We illustrate our discussion with examples of reverse logistics practice at IBM

Skipping orbits and enhanced resistivity in large-diameter InAs/GaSb antidot lattices

We investigated the magnetotransport properties of high-mobility InAs/GaSb antidot lattices. In addition to the usual commensurability features at low magnetic field we found a broad maximum of classical origin around 2.5 T. The latter can be ascribed to a class of rosetta type orbits encircling a single antidot. This is shown by both a simple transport calculation based on a classical Kubo formula and an analysis of the Poincare surface of section at different magnetic field values. At low temperatures we observe weak 1/B-periodic oscillations superimposed on the classical maximum.Comment: 4 pages, 4 Postscript figures, REVTeX, submitted to Phys Rev