Hub-and-spoke Research Articles

Relationship of hub and treatment characteristics with client outcomes in the initial Washington State hub and spoke cohort

IntroductionWashington State's Hub and Spoke (HS) approach aims to improve availability of opioid use disorder (OUD) treatment. Washington initially funded six hubs with expertise in medications for opioid use disorder (MOUD) that built care networks with referral and treatment partners (spokes). We assessed outcomes for the initial HS cohort, considering the role of HS and treatment characteristics. MethodsWe conducted a cohort-based observational study using 2017–2019 Medicaid claims data for 2841 HS participants aged 18–64, excluding those with past-month MOUD, in an intent-to-treat analysis. We describe treatment characteristics (MOUD type, treatment setting, and hub type at the initial HS visit, number of outpatient services in their first HS month), and six-month outcomes (MOUD continuity, emergency department (ED) utilization, hospitalization, and intensive SUD treatment). We used multivariable regressions to assess associations with six-month outcomes, adjusting for client characteristics. ResultsTwo-thirds (68 %) of participants received buprenorphine, 22 % methadone, 5 % naltrexone, and 5 % outpatient without MOUD for their initial visit. Within six months, 45 % had an ED visit, 14 % any hospitalization, and 18 % entered intensive SUD treatment. Only 24 % remained on MOUD for six months. Compared to buprenorphine, the methadone sample had higher odds of MOUD continuity (aOR = 2.81, 95%CI 2.21–3.55), and the naltrexone sample had lower odds (aOR = 0.36, 95%CI 0.19–0.66). FQHC/public health treatment settings had higher odds of MOUD continuity (aOR = 1.70, 95%CI 1.17–2.47) but hub type was not significant. MOUD continuity increased with 2+ outpatient services for the buprenorphine sample (aOR range 2.55–4.73). Odds of intensive SUD treatment were lower for the methadone sample, compared to buprenorphine (aOR = 0.16, 95%CI 0.11–0.23), all settings compared to SUD settings (aOR range 0.32–0.58), and SUD + MH and medical/hospital hubs compared to SUD only hubs (aOR range 0.28–0.41). ConclusionsMost participants did not attain six-month MOUD continuity, despite the HS approach, with variations by MOUD type and treatment setting. The number of outpatient services in the first month for buprenorphine clients was associated with greater odds of MOUD continuity and reduced odds of intensive SUD treatment. More work is needed to improve MOUD continuity for people with OUD within the HS model.

Carbon pricing and airline network selection: A four-network perspective

This paper investigates how variations in aviation carbon pricing influence the network choices of airlines and social planner. Beyond the traditional direct-flight (DF) network, hub-and-spoke (HS) network and mixed (MX) network, we incorporate the 2-hub (2 H) network into our analysis. The findings reveal that as carbon pricing costs increase, the optimal network configuration for airlines progresses sequentially through 2 H, MX and DF. This suggests that due to horizontal product differentiation, the inclusion of 2 H in the model renders the HS network—which is widely utilized by numerous major airlines—no longer the optimal choice for airlines. From the perspective of social planner, the optimal network configuration undergoes a progression from HS, 2 H, HS, MX, DF, MX to DF as carbon pricing costs rise. While the HS network may not align with the optimal choice for airlines, it has the potential to be the socially optimal network. Furthermore, the transition of socially optimal networks exhibits discontinuities, resulting in significant deviations from the network decisions made by airlines. Overall, this paper broadens the scope of network choices available to airlines by incorporating the 2 H network and offers theoretical insights for policy formulation by both airlines and society within the context of aviation carbon offset.

Hub-and-Spoke Network Optimization with Flow Delay Cost: The Case of Goods Delivery on Urban Logistics Networks in Eastern China

With respect to a traditional point-to-point (P-P) network, a hub-and-spoke (H-S) network not only uses a smaller number of links/paths but also utilizes the scale economy advantage on consolidated flows on hub–hub links and at hubs. However, the inevitable delays through hubs have always been a critical concern. Therefore, this paper develops an H-S model considering flow delay costs and applies the model to a logistics case in Eastern China. The integer quadratic term in the model’s objective function is linearized using the algebraic method. Our model is applied to develop an H-S network for its 13-node express package delivery operation, using the particle swarm optimization (PSO) algorithm. The results show using the H-S can save more than 14.1% of the total cost annually. The model also provides an applied case to the H-S configuration, especially for urban express delivery logistics in China.

Expanding access to medication treatment for opioid use disorders: Findings from the Washington State hub and spoke effort

BackgroundOpioid use disorder (OUD) is a leading cause of preventable death and injury nationwide. Efforts to increase the use of medication for opioid use disorder (MOUD) are needed. In 2017, Washington State implemented a Hub and Spoke (HS) model of care with the primary goal of expanding access to MOUD. We examined changes in MOUD utilization among Washington State Medicaid beneficiaries before and after HS implementation. MethodsWe used Medicaid claims data to examine longitudinal changes in MOUD use for beneficiaries with OUD. We conducted a comparative interrupted time series analysis to examine the association between HS policy implementation and rates of MOUD utilization, overall and by type of medication. ResultsBetween 2016 and 2019, a period of increasing OUD prevalence, rates of MOUD utilization among Washington Medicaid beneficiaries increased overall from 39.7 to 50.5. Following HS implementation, rates of MOUD use grew at a significantly greater rate in the HS cohort than in the non-HS cohort (β=0.54, SE=0.02, p< 0.0001, 95% CI 0.49, 0.59). Analyses by medication type show that this rate increase was primarily due to buprenorphine use (β= 0.61, SE= 0.02, p< 0.0001, 95% CI 0.57, 0.65). ConclusionImproved systems of care are needed to make MOUD accessible to all patients in need. The Washington HS model is one strategy that may facilitate and expand MOUD use, particularly buprenorphine. Over the study period, Washington State saw increased use of buprenorphine, which was an emphasis of their HS model.

Reframing mountain destinations from the perspective of tourist mobility: hub-and-spoke travel patterns

ABSTRACT In mountain areas, tourism destination management and branding generally follow administrative boundaries, representing a loss of competitiveness in the tourism sector for theses already remote destinations, in many cases, with under-developed tourism. Increasingly, researchers are claiming to consider tourist perspectives, not only in drawing up promotion strategies, but in rethinking management structures of tourism destinations, which are traditionally based on administrative boundaries. This can help to promote and manage mountain destinations more efficiently and provide an opportunity to economically develop these areas in decline through tourism. This research aims to detect new destination areas based on how tourists geographically consume mountain destinations in two European medium mountain ranges. To do so, the territoriality of tourist flows from accommodation hubs to surrounding attractions are analysed, representing hub-and spoke travel patterns. This enabled the detection of latent consumer-based mountain destinations, which were then contrasted with the official destinations limits in order to identify lost opportunities linked to mismatching between how mountain destinations are consumed and how they are managed. The findings show that consumer-based destinations are nothing like officially managed destinations and identify the most relevant factors determining hub-consumption systems. Finally, this research contributes to the discussion on increasing competitiveness of mountain destinations by adapting tourism branding and destination management to tourists.

Designing Airline Hub-and-Spoke Network and Fleet Size by a Biobjective Model Based on Passenger Preferences and Value of Time

This study presents a biobjective hub-and-spoke (HS) network design model for the global air passenger networks. The model explores the tradeoff between the total airline cost (airline preference) and lost time cost for passengers (user preference) as the model’s objectives. Most previous studies have focused on airline objectives and established HS networks based on the viewpoint of airlines, despite the importance of passenger objectives. Poor passenger service and inconvenience and dissatisfaction may lead to network breakdown. The major criteria for passenger dissatisfaction in HS networks are schedule and trip delays caused by nondirect flights. These delays (the lost time cost for passengers) are multiplied by the passengers’ value of time (VOT) and minimized as one of the model’s objectives. Another objective that is minimized is the transportation costs of the airline depending on the services provided (short-, medium-, and large-haul flights). The model is solved in a case study (Iranian Aeronautics Network) that is applied to the well-known yearbook of tourism statistics data. Pareto frontier was found for all candidate airports. Also, the number of aircraft required (short-, medium-, and large-haul), as well as the average load factor for different types of aircraft in various weights of the first objective (airline costs), was presented. The results of Pareto frontier indicated that Imam Khomeini International Airport should be selected as the global hub airport for Iran international flight network. Otherwise, Shiraz International Airport and Tabriz International Airport (as the first alternative), as well as Isfahan International Airport and Mashhad International Airport (as the second alternative), would be the best choices. The weight of the first objective (airline costs) seems to be between 0.7 to 1, a practical and logical weight that can reduce passenger costs (as the second objective) by 20% on average by adding only 15 long-haul, 40 medium-haul, and 37 short-haul aircraft to the airline’s fleet. Also, in this range, the average load factor for medium- and long-haul aircrafts is greater than 0.9, which seems to be ideal.

Identification of Urban Air Logistics Distribution Network Concepts

This study attempts to identify urban air logistics (UAL) operational concepts by synthesizing the urban freight transport (UFT) network configurations and urban air mobility (UAM) characteristics. UAL is gaining popularity as a quick and safe mode that has the potential to address several logistics challenges. This study has reviewed scientific papers identified using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework to understand the features of existing UFT distribution networks, unmanned aerial systems (UAS), and UAM. The cross analysis considered UFT features such as the parcel’s weight, delivery type (time sensitivity, customer-to-customer, business-to-consumer, or business-to-business), and UFT distribution network types and compared them against the features of UAS such as maximum take-off weight, range, and infrastructure requirements (drone ports). The analysis identified three types of UAL operational concepts: door-to-door direct (D2DD), hybrid, and multimodal. Lightweight deliveries can be operated using D2DD and hybrid through point-to-point (P-P) and extended P-P network concepts. The hybrid concept uses an intermediate drop-off location to deliver goods. Hub-and-spoke (H-S), extended H-S, and trunk line with collecting/distribution network designs can be used for heavyweight cargo operations. D2DD versus hybrid/multimodal concepts were compared based on six thematic clusters (societal implications, safety and security, ethics, environmental issues, public acceptance, and urban planning and infrastructure). This study identified that technological development and innovation could reduce social implications and ethical challenges. Furthermore, public willingness and economic feasibility will determine the success of the operational concepts. The identified UAL operational concepts, network designs, and challenges will help to conduct further research in this subject area.

Bundling challenges Hub-and-Spoke networks

A typical implementation of the Hub-and-Spoke (HS) structure in the rail system is the new rail-rail transshipment terminal, which facilitates the rapid and simultaneous transfer between different traffic flows. Based on literature and focus group interviews, this paper identifies the bundled tasks involved in implementing the HS structure at network and terminal levels and analyzes the potential challenges in terminal operations.

Bundling challenges Hub-and-Spoke networks

A typical implementation of the Hub-and-Spoke (HS) structure in the rail system is the new rail-rail transshipment terminal, which facilitates the rapid and simultaneous transfer between different traffic flows. Based on literature and focus group interviews, this paper identifies the bundled tasks involved in implementing the HS structure at network and terminal levels and analyzes the potential challenges in terminal operations.

Hub location problem considering spoke links with incentive-dependent capacities

This study proposes a hub-and-spoke (HS) network in which the capacity of a spoke link depends on the incentive provided to the transporters. The incentives influence the capacities of the spoke links, which in turn affect the hub selections and flow assignment. A mixed integer convex programming model is developed to optimize the proposed HS network. The model minimizes total transport cost by locating p hubs, routing flows between origin–destination (OD) pairs and determining the incentives on spoke links. A customized outer-approximation algorithm is presented to provide exact solutions to the developed model, which is difficult to solve optimally within acceptable computational times for large-scale instances. An approximation algorithm based on the stepwise linearization method is then developed to provide suboptimal solutions. The developed model and algorithms are validated in computational experiments with different problem scales. The experiments demonstrate that the proposed HS network tends to route the flows on more spoke links, balance the transport costs on the potential paths between OD pairs and serve more demands with lower transport costs, when compared with the HS network with fixed capacities.

Decision onRegional Logistics Network Based on H-S and P-P Network: Taking Tobacco Transportation Logistics as anExample

Objectives: The logistics hub construction has always been the short board of logistics network planning in China. In order to improve the decision-making efficiency of logistics enterprise’s hub selection and reduce its comprehensive operation cost, this paper establishes a cost difference model for hub-and-spoke(H-S) and point-to-point(P-P) networks considering the fixed cost of hubs, transportation and route costs based on the 0-1 integer nonlinear programming. The model aims at minimizing the cost difference between the two networks, and divides the fixed cost of the hubs into three situations: full lease, lease and self-built, and fully self-built. Finally, this paper takes tobacco transportation logistics as an example, and use particle swarm algorithm to solve the model by using tobacco transportation logistics data of a logistics enterprise in Jiangsu Province. The results show that: (i) in the case of complete leasing, the total cost of the H-S network decreases with the increase of the number of hubs, and the cost change has a point of intersection with the total cost of the P-P network;(ii) when the lease and self-build are mixed, the increase is first reduced and then increased, it is U-shaped and has a minimum value, and there are two intersections with the total cost of the P-P network;(iii) the situation of completely self-built and fully leased is just the opposite. This paper takes tobacco transportation logistics as a representative, and provides a reference for logistics companies to choose the appropriate regional logistics network structure and different pivot points.

Exploring the factors influencing the cost-effective design of hub-and-spoke and point-to-point networks in maritime transport using a bi-level optimization model

Hub-and-spoke (HS) networks are cost-effective because they allow the realization of economies of density. However, the cost of point-to-point (PP) networks may be lower than that of HS networks when certain conditions, such as cargo demand, bunker price, vessel size, and the shippers’ value of time change. This study explores the factors that influence the cost-effectiveness of HS and PP networks. We developed a mixed-integer programming model that allows for bi-level optimization between shipping lines and shippers. As a case study, we applied it to Chinese and Japanese ports, with both HS and PP networks. We found that high cargo demand increases the use of PP networks while enlarging vessel size increases the use of HS networks. These findings enable us to predict the occurrence of hubbing—shifting from a PP to an HS network—and de-hubbing—shifting from an HS to a PP network.

International Airline Alliance Network Design with Uncertainty

This paper addresses the alliance route network design problem considering uncertainty in the unit transportation cost. An alliance route network was constructed based on a hub-and-spoke (HS) network, in which airlines could achieve inter-area passenger transport through their international gateways. The design problem was formulated with a robust model containing a set of uncertain cost parameters. The model was established based on a three-subscript model of an HS network. A case study with real-world data was used to test the proposed model. The results showed that this robust solution can reduce the impact of cost uncertainty.

Simulating long-term performance of regional distribution centers in archipelagic logistics systems

Indonesia has reevaluated its archipelagic logistics system to implement a strategic shift from a point-to-point network to a hub-and-spoke network, with a plan to establish seven new regional distribution centers (RDCs). To supplement the previous qualitative assessment of the plan and to potentially justify continuing with its implementation, this paper aims to evaluate the prospective long-term performance of the planned RDCs within a hub-and-spoke (HS) network. The chosen methodology for this analysis is a hybrid of optimization and simulation, using an agent-based modeling and simulation platform that incorporates a geographic information system (GIS) element to provide a realistic geographical context. This constitutes a relatively novel innovation in logistics research. Experiments were developed to estimate the logistics performance of the hub-and-spoke network and planned RDCs, as well as to identify potential problems such as bottlenecks at the RDCs and the relative (in)efficiency of the selected multimodal transport. Transport costs, inventory costs, and the order backlog of RDCs are evaluated based on the average results from 100 replications. Outcomes from the model are validated against empirical data on Indonesia’s logistics costs from the World Bank. Model results indicate that the hub-and-spoke network performs better than the point-to-point network when it comes to transportation costs. Since this is found to be the dominant element of total logistics costs, appropriate modal choice and route optimization are, therefore, critical to reducing logistics costs. The planned RDCs are found to have significant imbalance in their loadings, which is likely to produce bottlenecks. The paper concludes that a planned move to a hub-and spoke system is appropriate and that the planned investment in the RDCs is therefore justified. However, there is a need to streamline the predicted loadings at the RDCs to avoid bottlenecks. Our results suggest that the government should reopen the case and reevaluate the locations and coverage of each RDC. More generically, it is concluded that the application of hybrid optimization and simulation using agent-based modeling and simulation is feasible and the methodological approach adopted herein is generalizable to other archipelagic logistics systems.

Vascular Network Transfer Audit: Evaluation of Transfer Time to Theatre for Diabetic Patients Requiring Emergency Vascular Surgery in Hub-Arterial Site

Introduction: Since the establishment of vascular network across our region under hub-and-spoke model, the arterial centre involved in this study receives referrals for diabetic foot problems requiring surgical input. With active diabetic foot problems, there is often the need for urgent assessment, investigation and intervention. The reduced vascular contribution from non-arterial centres have raised concerns in providing a service that minimises delays and prioritises patients according to clinical need, not geographical location We aimed to study the efficiency of the regional network by analysing transfer time to theatre for patients with diabetic foot problem. Methods: All patients who had lower limb amputation +/- debridement from October 2017 to October 2018 were identified from the local theatre database. Whether admitted directly to local hub or referred from the spoke sites, each patient was tracked to its original point of referral, time and date of referral was established. Knife to skin time was identified for each patient, and subsequently transfer time to theatre (TTT) - from referral to knife to skin time - was calculated for all patients. Non-diabetic and non-emergency cases were identified and excluded based on clinical records, urgency of transfer to theatre from admission, CEPOD category and inflammatory markers on admission. Transfer Time to Theatre (TTT) was calculated for 3 groups of patients; those admitted directly to the Hub site, and two other groups from Spoke sites. Results: Total of 109 diabetic patients with average age of 62 were identified who had emergency lower limb amputation +/- debridement over the course of 12 months. The average TTT was calculated for each group, TTT for Hub was 23hrs42min, for 'spoke-1' and 'spoke-2' was 39hrs30min and 32hrs42min respectively. Analysis of data sets indicated statistically significant (P< 0.05) difference in TTT for those who were admitted directly to the hub, compared to the ones referred and admitted from the spoke sites. Conclusion: The data above highlighted significant inequalities and delays across the network. Given the high morbidity and mortality of diabetic patients, we are using our findings to devise and implement guidelines to improve transfer links to arterial sites. Diabetic patients requiring emergency surgical input have high morbidity and mortality, hence it is essential to minimise delay in transfer, improve communication across sites and improve transport links. Our data highlighted significant inequalities and delays across the network. Providing that the national service specification has already defined that vascular surgery should be delivered via a hub-and spoke network model, it is essential to ensure services are running smoothly and to devise guidelines and protocols to ensure smooth transfer to arterial sites. The findings of this project led to the design and implementation of regional guidelines and initiation of prospective study which is being carried out at the moment, for identifications of pitfalls that caused the delays across the network. Disclosure: None of the authors has a financial interest or commercial association to declare in relation to the content of this project. All patient data was anonymised prior to data analysis.

A Hungarian and Ukrainian Competitors’ Network: A Spatial Network Analysis Perspective

In this paper, the spatial dimensions of a transboundary, coopetitive (coopetition: cooperation of rivals) network, established by restaurant owners, are scrutinized empirically by applying advanced toolkits of spatial network analysis (SpNA). The paper emphasizes that the coopetitive network has geographical extensions, and on the other hand, interactions between vertices generate network space. The new type of economic network could thus be analyzed by SpNA to understand the spatial characteristics of a rivals’ network at transboundary level. The paper may be referred to as cutting-edge research, because on one hand, it dissects a new type of economic network (coopetitive networks) and on the other hand, a new method is utilized (SpNA) to study the geographical parameters of inter-firm relationships. This approach emerges as a novel method. As a result, the paper provides significant, fruitful and new findings in both network science and urban economics as well. By employing metrics of SpNA, the main spatial traits of the coopetitive network can be mapped, such as the circumference, spatial structure, diameter, spatial density, spatial small world phenomenon, and global connectivity of the network. The results show that the coopetitive network possesses hub-and spoke spatial framework, in which the hub is localized far from the cluster of players. Moreover, the coopetitive interaction does not require face-to-face nexus, because the focal firm communicates with them via IT devices. The coopetitive activities contribute significantly to the urban economic growth. The main agent (the hub) ought to be supported by the regional development policy at the local and inter-urban geographical scale as well.

Airline hub-and-spoke network design based on airport capacity envelope curve: A practical view

Abstract In this study, a new practical airline hub location model with hub capacity decision is presented based on airport capacity envelope functions. In the literature on hub location with the hub capacity decision, the capacity of hub nodes has been expressed as a constant. In real-life air network, airport capacity is expressed as some functions of arrival and departure of flights according to the functions of airport capacity envelope curve. Therefore, to make the mathematical models of Hub Location Problem (HLP) compatible with the reality, the hub capacity was considered as a function of arrival and departure of flights based on the hub capacity envelope curve. Also, this study is the first to consider the possibility of direct trip between two non-hub nodes together with hub capacity decision problem in a multiple allocation model. The presented model is solved exactly for some small-scale versions of Iranian airline network and compared to a hub capacity model with a constant capacity decision. The capacity of Iranian airports is calculated based on flight statistics reported in 2015. For each hub airport, three scenarios are considered to gain 30%, 60% and 90% airport capacity from the perspective of the airline. Also, to solve the proposed model at a large scale, an Adaptive Large Neighborhood Search (ALNS) with some new removal and insertion moves is proposed and applied to a large-scale version of Iranian airline network. The results showed that disregard for the airport capacity envelope curve can increase the airline operational costs and lead to the design of a non-optimal Hub and Spoke (HS) network. Accordingly, some recommendations based on the results are presented for this real network.

Modeling the selection of airline network structure in a competitive environment

This paper deals with modeling the selection of airline network structures for airlines operating in a competitive environment. In order to capture interactions between competing airlines when choosing the structure of their networks, the effects of product differentiation based on prices, flight frequencies, seat accessibility and route length have been considered. Competing airlines are supposed to be able to choose either point-to-point (PP) or hub-and-spoke (HS) network structure. Each choice is expected to have different implications on their profitability (i.e. costs and revenues) strongly influenced by different products offered to passengers. The main results indicate that there are direct benefits to users/passengers due to the simultaneous increase of flight frequencies and unchanging prices, which leads to the socially-optimal choices of prices and flight frequencies. In addition, modeling which includes route lengths opens new perspectives on coexistence between the two different business models. Integration of these parameters results in selecting an airline network structure model in a competitive environment which enables passengers to differentiate among the offered transport services.

Intermodal freight network incorporating hub-and-spoke and direct calls for the archipelagic Philippines

Compared with point-to-point (PTP) transport, a hub-and-spoke (HS) network benefits from consolidation of cargoes in hubs, leading to lower average costs for hub-to-hub transport because of scale economies. This article explores the use of intermodal road – Roll-on Roll-off (RoRo) transport, in complement with container transport, that is, in a combined HS and PTP network topology for the archipelagic Philippines. The mixed HS network is modeled to incorporate the properties of multiple allocations, non-restrictive networking policy and general hub network topology. The large network problem is solved by a heuristic that uses Lagrangian relaxation as a starting point. The model is able to locate hub ports where cases of intermodal road-RoRo and container transport could transship and be used complementarily. It is shown that considerable savings in total network costs could be realized with a mixed network, as compared with a purely PTP one.

Environmental impact of distribution network design: the case of Korea

PurposeThe purpose of this paper is to analyze the environmental impact of distribution network design.Design/methodology/approachTypical distribution networks are identified and modeled through interviews with logistics companies in Korea. CO2emission is calculated for the distribution network models to evaluate the environmental impact of different network designs. In addition, economic and customer service performances are evaluated to provide realistic and balanced solutions to supply chain managers.FindingsIt is suggested that hybrid networks combining Hub-and-Spoke (HS) and Point-to-Point (PP) networks with a small number of sub-terminals are the most effective in both environmental and customer service aspects, whereas HS network is the most cost-effective.Research limitations/implicationsThe analysis in this study is based on certain assumptions, and hence full application of these results to specific cases is limited. The combination of PP network with HS network is suggested, forming a hybrid network, and CO2mitigation policies need to consider support schemes that can influence a firm’s decision making in relation to network design.Originality/valueLittle attention, however, has been paid to the environmental impact of distribution network design in the exiting literature. This study is a rare attempt at evaluating the environmental impact of distribution network design and may provide valuable implications to policy-makers and practitioners in logistics and manufacturing companies.