•Myanmar has experienced extremely rapid agricultural mechanization since 2011.•Agricultural machinery is close to scale-neutral at point of use.•Small farm sizes do not hinder uptake due to ...availability of outsourcing services.•Demand for machines is driven by labor scarcity, timeliness, risk, drudgery aversion.•Supply of machine outsourcing services facilitated by reforms to trade, banking, land tenure.
The past decade has seen a resurgence of interest in the role of mechanization in agricultural development. This literature has given rise to debates over the design of institutions and policies to facilitate accelerated mechanization, the role of outsourcing services in overcoming problems of access to machinery, and questions regarding the future of smallholder agriculture. We contribute to these debates using two pairs of complementary demand side (farm household) and supply side (agricultural machinery retailer) surveys, implemented in Myanmar in 2016 and 2017 across two major agro-ecological zones. Our analysis provides evidence that extremely rapid agricultural mechanization took place during the period of political and economic reforms from 2011 to 2020. In both zones surveyed, use of machinery for land preparation, harvesting, and threshing was close to scale-neutral due to a dynamic outsourcing services market. Rather than representing a single transformational change, mechanization’s broad appeal to farm households results from an accumulation of incremental, overlapping, complementary advantages. These include labor savings, reduced drudgery, convenience, increased speed and timeliness of operations, improved ability to manage weather-related risks, and reduced loss of grain during harvesting. We provide examples of policies on trade, finance, and land tenure that contributed to this transformation with practical implications for ongoing policy debates on mechanization in other countries, and suggest some generalizable lessons.
•We present maintenance optimization models for cases with known time-varying costs.•Linear and Mixed-integer programming formulations are given for the Replacement models with time-varying ...costs.•Coordinating preventive maintenance with low downtime cost periods can save up to 20%.•A case study for a wind turbine gearbox is presented with savings between 2% and 20%.•Low downtime cost periods substantially effect optimal maintenance intervals.
In this paper, we introduce a new, single-component model for maintenance optimization under time-varying costs, specifically oriented at offshore wind turbine maintenance. We extend the standard age replacement policy (ARP), block replacement policy (BRP) and modified block replacement policy (MBRP) to address time-varying costs. We prove that an optimal maintenance policy under time-varying costs is a time-dependent ARP policy. Via a discretization of time, the optimal time-dependent ARP can be found using a linear programming formulation. We also present mixed integer linear programming models for parameter optimization of BRP and MBRP. We present a business case and apply our policies for maintenance planning of a wind turbine gearbox and show that we can achieve savings up-to 23%.
Assembly line balancing problems (ALBP) have plagued scholars and practitioners for decades. This paper investigates a new assembly system called flexible assembly line (FAL) derived from empirical ...observations in an air-conditioner assembly workshop. FAL can avoid the ALBP itself thanks to its structural flexibility and reconfigurability. However, field investigation highlights new challenges in the FAL - the mismatch between production (assembly) and intralogistics (material supply) leads to long waiting/idle time and workflow chaos, consequently lowers productivity and increases backorders. The production-intralogistics (PiL) processes are spatiotemporally coupled and interactional. Its complexity is much higher than considering the production or intralogistics optimization solely. And the PiL processes are further complicated by uncertain events such as new job arrivals, stochastic operational time, and equipment failures. The advent of Industry 4.0 technologies shows the tremendous potentials to revolutionize the contemporary notions of production management. Massive production data can be collected and analyzed in real-time. Nevertheless, there is little methodological research regarding utilizing real-time data to support production decisions under uncertainties. Thus, how to leverage real-time data collected in Industry 4.0 environments to support the decision-making of PiL processes for achieving a matched, coordinated, and synchronous operations management under various uncertainties, is a novel research problem. This paper develops a five-phase Graduation intelligent Manufacturing System (GiMS) to achieve PiL synchronization with flexibility and resilience. The underlying principles and rationale of GiMS are formulated as a synchronization mechanism, which includes a graph-theory based clustering for planning/scheduling and real-time decentralized ticketing for execution/control. Comprehensive numerical results validate the superiority of GiMS and the benefits of visibility and traceability in various scenarios. Moreover, the effects of uncertainties and trolley capacity are investigated in the sensitivity analysis.
•A novel production-intralogistics synchronization problem in flexible assembly lines is studied.•A 5-phase implementation framework of GiMS is developed for PiL Synchronization in FAL.•A flexible and resilient real-time decision-making mechanism under GiMS is proposed.•Numerical study has validated the superiority of the proposed GiMS and real-time data.•The effects of uncertainty level and trolley capacity are studied in the sensitivity analysis.
Proprietary parts as a secondary market strategy Kleber, Rainer; Quariguasi Frota Neto, João; Reimann, Marc
European journal of operational research,
06/2020, Volume:
283, Issue:
3
Journal Article
Peer reviewed
Open access
•Original equipment manufacturer and independent remanufacturer compete.•Product-design decisions impact competition on the secondary market.•Manufacturers control the secondary market by suitably ...pricing proprietary parts.•The manufacturer can remanufacture more items than the remanufacturer would.
Introducing proprietary parts to gain a competitive edge is a well-known, yet poorly understood strategy original equipment manufacturers (OEMs) adopt. In this paper, we consider an OEM who sells new products and competes with an independent remanufacturer (IR) selling remanufactured products. The OEM contemplates proprietary parts to manage the secondary market for remanufactured products. Thereby, the OEM designs its product to balance the trade-off between the cost of proprietariness and the extra income from selling the proprietary spare parts to the IR. Deterring market entry by the IR through prohibitively pricing the proprietary spare parts, an OEM strategy observed in several industries, is only optimal when the willingness-to-pay for remanufactured products is low. Otherwise, the OEM benefits more from sharing the secondary market profits with the IR through the use of proprietary parts. Finally, we find that the OEM can also use proprietary parts to strategically deter entry by the IR, discouraging her from collecting cores. This can support the OEM’s decisions to engage in remanufacturing even in the case of a collection cost disadvantage. While the introduction of proprietary parts is detrimental to both IRs and consumers, we show that for consumers such loss is reduced when the OEM engages in product remanufacturing.
•We combine corrective, periodic, and condition-based maintenance in a hybrid policy.•We propose an opportunistic threshold to avoid setup costs and future failures.•We propose an intervention ...threshold to avoid imminent failures.•We provide analytical expressions to evaluate the maintenance cost and downtime.•We offer a smooth transition to implement condition-based maintenance in practice.
Condition-based maintenance (CBM) makes use of the actual condition of the component to decide when to maintain and/or replace the component, thereby maximising the lifetime of the machine, while minimising the number of service interventions. In this paper we combine CBM on one (monitored) component, with periodic preventive maintenance (PM) and corrective maintenance (CM) on the other components of the same machine/system. We implement two thresholds on the degradation level to decide when to service the monitored component: when the degradation level of the monitored component surpasses a first ‘opportunistic’ threshold, the monitored component will be serviced together with other components, for instance with a (planned) PM intervention, or upon breakdown of another component, requiring CM. In case none of these opportunities have taken place, and the degradation level surpasses a second ‘intervention’ threshold, an additional maintenance intervention is planned for the monitored component in order to prevent a failure. Both thresholds are optimised to minimise the total expected maintenance costs of the monitored component, or to minimise the downtime of the machine due to maintenance on the monitored component. We perform an extensive numerical experiment to demonstrate the potential gains of this hybrid policy with two thresholds compared to using a traditional PM policy, and we identify its key drivers of performance. We also benchmark our results when only one threshold is implemented. Our model is validated and applied at an OEM in the compressed air and generator industry.
•Research supply chain contract in the medical equipment industry.•Investigate quality efforts in medical supply chains with patient concerns.•Introduce our models into a case study and conduct ...sensitivity analysis.•Find nonlinear relationship among quality efforts, patient benefits, and performance.•Find optimized quality efforts can improve supply chain profits.
We consider supply chain (SC) contracts in a new setting, the medical equipment industry, where concern for patient benefits is essential and quality efforts are critical for profits compared with supply chains (SCs) in other industries. It remains unclear how quality efforts and patient concern levels affect SC performance and how medical equipment manufacturers’ quality effort levels are linked to their patient concern levels. This study focuses on the impact of a manufacturer's and a retailer's patient concern levels on optimal pricing and quality decisions in an SC consisting of a manufacturer facing quality effort-dependent demand and a retailer in the medical equipment industry. We use the Stackelberg game to characterize and determine the optimal operational decisions in five scenarios and address the effects of patient concern levels under above five scenarios. A real case is studied and shows that optimized quality efforts can improve SC profits. The parameters settings are derived from the real data. Our findings bridge the gap between SC quality management and patient benefits and help to understand contract design in relation to patient concerns in different SC structures. This paper is among the earliest to investigate quality efforts for SC contract design in relation to patient concerns and to study SC contract design in the medical equipment industry. Our managerial insights are expected to help manufacturers move toward better quality effort decisions considering patient benefits and are also applicable to other SCs with effort-dependent demand and the effect of altruistic preferences.
When does a nuclear-armed state's provision of security guarantees to a militarily threatened ally inhibit the ally's nuclear weapons ambitions? Although the established security model of nuclear ...proliferation posits that clients will prefer to depend on a patron's extended nuclear deterrent, this proposition overlooks how military threats and doubts about the patron's intentions encourage clients to seek nuclear weapons of their own. To resolve this indeterminacy in the security model's explanation of nuclear restraint, it is necessary to account for the patron's use of alliance coercion, a strategy consisting of conditional threats of military abandonment to obtain compliance with the patron's demands. This strategy succeeds when the client is militarily dependent on the patron and when the patron provides assurances that threats of abandonment are conditional on the client's nuclear choices. Historical evidence from West Germany's nuclear decisionmaking provides a test of this logic. Contrary to the common belief among nonproliferation scholars, German leaders persistently doubted the credibility and durability of U.S. security guarantees and sought to acquire an independent nuclear deterrent. Rather than preferring to renounce nuclear armament, Germany was compelled to do so by U.S. threats of military abandonment, contradicting the established logic of the security model and affirming the logic of alliance coercion.
Since the mid-1990s, the U.S. civilian gun stock has grown from approximately 192 million (65 million handguns) to approximately 265 million (113 million handguns). In 2015, gun owners owned more ...weapons and were more likely to own both handguns and long guns than in 1994. As in 1994, ownership in 2015 was highly concentrated: the median owner owned two, but the 8 percent of all owners who owned ten or more accounted for 39 percent of the stock. Approximately seventy million firearms changed hands within the past five years (from 2011 to 2015); most were purchased. Two and a half percent of Americans had guns stolen within the past five years, accounting for an estimated five hundred thousand guns per year.
•Develops the concept of knowledge recombination novelty in an alliance context•Finds that unique component ties in alliance partner knowledge pools influence focal firm's knowledge utilization from ...this partner•Finds that focal firm's own experience with creating unique component ties does not moderate this main relationship•Highlights the importance of conceptualizing alliance partner knowledge pools as a set of interdependent components, rather than independent components
Whereas extant alliance research tends to consider the knowledge pool of partner firms as a set of independent components, we highlight that alliance partners’ components are interconnected. In particular, we introduce the concept of alliance partner knowledge recombination novelty – i.e., the extent to which an alliance partner has created component ties that no other firm within the industry has created – and hypothesize that it has an inverted U-shaped relationship with the focal firm's utilization of the alliance partner's knowledge. We also expect this relationship to be moderated by the focal firm's own knowledge recombination novelty. Analyzing 313 R&D alliance dyads of 70 firms in the fuel cell industry, we find support for the hypothesized inverted U-shaped relationship between an alliance partner's knowledge recombination novelty and the focal firm's knowledge utilization from the alliance partner. However, we do not find support for a moderation effect of the focal firm's knowledge recombination novelty. Based on these findings, we demonstrate the importance of framing alliance partner knowledge pools as sets of interconnected components, where alliance partners’ history of knowledge recombination shapes the focal firm's knowledge utilization rates.
This paper identifies profound contradictions within and across nuclear deterrence strategies that evolved in response to the proliferation and modernization of nuclear weapons. To reconcile theory ...with practice, we summarize the theoretical assumptions and implications of nuclear strategy. Informed by these discussions, we develop a decision-theoretic model of deterrence based on power transition theory. We explore conditions for the stability of deterrence and link outcomes to policy decisions. The conditions for conflict emerge when a dissatisfied nuclear nation is threatened with conventional loss, when conventional and nuclear parity is achieved and if dissatisfied non-state actors acquire even minimal nuclear capabilities.
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