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743 items in total found

Journal Articles | 2019

Trust in humanitarian operations: a content analytic approach for an Indian NGO

Prakash Awasthy, K.V. Gopakumar, Sirish Kumar Gouda, and Tanushree Haldar

INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH

Trust between partners, a key element enabling coordination across supply chains, has recently started gaining attention in humanitarian operations literature. Yet, empirical examination of this concept is scant. Borrowing from extant literature on trust within organisational behaviour stream, this paper aims to empirically verify trust formation types: companion, competence and commitment, in a disaster relief supply chain using primary and secondary data from an Indian Humanitarian relief organisation (HRO). Further, we identify variations in trust formation during disaster relief activities and developmental programmes, and between upstream and downstream partners of a humanitarian relief organisation. Based on the results of our content analysis, we contend that while companion based trust is significantly more prevalent during developmental programmes, competence based trust is important during both disaster periods and otherwise. We also find that there are significant differences in the trust formation between upstream and downstream partners and the HRO. This study has significant theoretical and practical implications on identifying the role of trust in humanitarian operations.

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Journal Articles | 2019

An examination of factors driving big 4 audit fee premiums: Evidence from India's audit market

Joshy Jacob, Naman Desai, and Sobhesh Kumar Agarwalla

Accounting Horizons

This study examines fee premiums earned by Big 4 auditors in India and identifies the primary reason for such fee premiums. There are three primary drivers of Big 4 fee premiums. Big 4 auditors charge a fee premium for their reputation, for providing a superior quality of audit, and for indemnifying losses for a company's stakeholders. Since the risk of auditor litigation in India is relatively low, Big 4 premiums in India would not be driven by the need for auditors to indemnify losses. The results indicate that Big 4 auditors earn significantly higher fees in India and also that their clients enjoy significantly higher earnings response coefficients compared to non-Big 4 clients. However, there is no difference in the quality of audit provided by Big 4 and non-Big 4 auditors as measured by the magnitude of reported discretionary accruals.

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Journal Articles | 2019

Non-optimality of state by state monopoly pricing with demand uncertainty: An example

James Peck and Jeevant Rampal

Economics Letters

This paper considers a monopoly’s profit maximizing problem, where there is a continuum of consumers with unit demand, and valuations are given by one of two possible demand distributions/states. The firm’s problem is to maximize profits by choosing an optimal mechanism among direct revelation mechanisms that satisfy interim incentive compatibility and ex-post individual rationality. We show that setting the monopoly price in each demand state may not be optimal.

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Journal Articles | 2019

Strategizing in small informal retailers in India: Home delivery as a strategic practice

Atul Arun Pathak and George Kandathil

Asia Pacific Journal of Management

Small informally organized family-owned grocery retailers—kiranas—are ubiquitous in India and have retained market dominance while facing increasing competition from large formally organized retailers (FORs). Yet, strategy literature has under-explored such informal businesses. We explore kiranas’ distinct strategic practices that give them competitive advantage over FORs, generating kiranas’ sustained market dominance. To explore kiranas’ informal strategizing, grounded theoretic analysis of our multi-year case study suggested the employment of strategy as practice (SAP) framework, enriched with the social exchange theory (SET) concepts of trust and reciprocity. We find that the kiranas’ sustained enactment of strategic practice such as free-of-charge home-delivery significantly depends on contextually rich, reciprocity-based social exchange relationships with customers which evolve through praxes involving continuous exchange of trust. The practice enactment and exchange relationships constitute strategy-practitioner’s emerging dual-identity, which in turn reinforces the practices, generating a self-reinforcing cycle of practice enhancement. Within this cyclic relationship, an inimitable enactment of a strategic practice can be a key source of competitive advantage for informally organized small retail retailers over large FORs. By linking two unconnected prominent approaches to understanding patterns of workplace interactions, namely SAP and SET, the study opens theoretical avenues for exploring strategizing of informal businesses.

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Journal Articles | 2019

Identifying defective network components through restricted group testing

Diptesh Ghosh

OPSEARCH

In this paper, we consider a network of switches in which some of the switches may malfunction. Our aim is to find out efficiently (a) if any of the switches in a network of switches are defective, and (b) if there are defective switches, to identify those switches. We find an optimal solution for the first problem and a heuristic solution to the second, and demonstrate the feasibility of our approach through computational experiments.

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Journal Articles | 2019

Robotized and automated warehouse systems: Review and recent developments

Kaveh Azadeh, Debjit Roy, and Rene De Koster

Transportation Science

Robotic handling systems are increasingly applied in distribution centers. They require little space, provide flexibility in managing varying demand requirements, and are able to work 24/7. This makes them particularly fit for e-commerce operations. This paper reviews new categories of automated and robotic handling systems, such as shuttle-based storage and retrieval systems, shuttle-based compact storage systems, and robotic mobile fulfillment systems. For each system, we categorize the literature in three groups: system analysis, design optimization, and operations planning and control. Our focus is to identify the research issue and operations research modeling methodology adopted to analyze the problem. We find that many new robotic systems and applications have hardly been studied in academic literature, despite their increasing use in practice. Because of unique system features (such as autonomous control, flexible layout, networked and dynamic operation), new models and methods are needed to address the design and operational control challenges for such systems, in particular, for the integration of subsystems. Integrated robotic warehouse systems will form the next category of warehouses. All vital warehouse design, planning, and control logic, such as methods to design layout, storage and order-picking system selection, storage slotting, order batching, picker routing, and picker to order assignment, will have to be revisited for new robotized warehouses.

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Journal Articles | 2019

Design, modeling, and analysis of vertical robotic storage and retrieval systems

Debjit Roy, Kaveh Azadeh, and Rene De Koster

Transportation Science

Autonomous vehicle-based storage and retrieval systems are commonly used in many fulfillment centers (e.g., e-commerce warehouses), because they allow a high- and flexible-throughput capacity. In these systems, roaming robots transport loads between a storage location and a workstation. Two main variants exist: horizontal, where the robots only move horizontally and use lifts for vertical transport, and a new variant vertical, where the robots can also travel vertically in the rack. This paper builds a framework to analyze the performance of the vertical system and compare its throughput capacity with the horizontal system. We build closed queueing network models for this that, in turn, are used to optimize the design. The results show that the optimal height-to-width ratio of a vertical system is around one. Because a large number of system robots may lead to blocking and delays, we compare the effects of different robot blocking protocols on the system throughput: robot Recirculation and Wait-on-Spot. The Wait-on-Spot policy produces a higher system throughput when the number of robots in the system is small. However, for a large number of robots in the system, the Recirculation policy dominates the Wait-on-Spot policy. Finally, we compare the operational costs of the vertical and horizontal transport systems. For systems with one load/unload (L/U) point, the vertical system always produces a similar or higher system throughput with a lower operating cost compared with the horizontal system with a discrete lift. It also outperforms the horizontal system with a continuous lift in systems with two L/U points.

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Journal Articles | 2019

Inventory allocation in robotic mobile fulfillment systems

Tim Lamballais Tessensohn, Debjit Roy, and Rene B M De Koster

IISE Transactions

A Robotic Mobile Fulfillment System is a recently developed automated, parts-to-picker material handling system. Robots can move storage shelves, also known as inventory pods, between the storage area and the workstations and can continually reposition them during operations. This article shows how to optimize three key decision variables: (i) the number of pods per SKU; (ii) the ratio of the number of pick stations to replenishment stations; and (iii) the replenishment level per pod. Our results show that throughput performance improves substantially when inventory is spread across multiple pods, when an optimum ratio between the number of pick stations to replenishment stations is achieved and when a pod is replenished before it is completely empty. This article contributes methodologically by introducing a new type of Semi-Open Queueing Network (SOQN): cross-class matching multi-class SOQN, by deriving necessary stability conditions, and by introducing a novel interpretation of the classes.

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Journal Articles | 2019

Integrated storage-order picking systems: Technology, performance models, and design insights

ElenaTappiaa, Debjit Roy, MarcoMelacini, and René De Koster

European Journal of Operational Research

In many warehouses shuttle-based technologies have replaced the traditional AS/R system based storage technologies. The impact these systems have on downstream order picking performance is largely unknown. To study the interactions between upstream storage and downstream picking systems, we develop a novel analytical model for integrated storage and order picking systems. The resulting semi-open queuing model is solved using the matrix-geometric method. Using the queuing network model, we are able to study the effect of storage system technology on order throughput times, and the effect of the picking station input buffer size on order picking performance. Further, we analyze the effect of a constant work-in-process (CONWIP) control for orders on system performance. Our results indicate that using SBS/R instead of AS/R-based storage systems yields investment cost savings (i.e., fewer aisles in the storage area and fewer picking stations), paired with a lower total throughput time at a given order arrival rate. Numerical studies show how the total throughput time, first, benefits and then becomes stable by increasing the input buffer size at the picking stations. Retrieving item tote at the storage system in advance with respect to the picker availability is also advantageous, especially in the SBS/R system.

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Journal Articles | 2019

From courts to markets: New evidence on enforcement of pharmaceutical bans in India

Chirantan Chatterjee, Debi Prasad Mohapatra, and Manuel Estay

Social Science & Medicine

Regulatory enforcement of product safety standards given health concerns, whether it is in romaine lettuce, smartphones or cars, is emerging to be a challenge for global public health. This is particularly true for developing economies with fragile institutions. In this context, recent studies on Indian pharmaceutical markets provide evidence suggesting that the sector is a hub for substandard quality of medicines. Departing from these prior studies which use randomly collected samples, we reinvestigate this question using novel pan-India market sales data of banned medicines from 0.75 million pharmacists and chemists in India. We find that indeed such medicines get sold in India even after bans are imposed on them in the period 2007 to 2013. However, there is a general decline in demand post ban for our focal molecules suggesting broad adherence to bans. We also observe regional heterogeneity in prevalence of banned medicines sold between rich and poor regions of India with the former counterintuitively showing more sales. That said, while Ozawa et al. (2018) argue that prevalence of substandard medicines is around 13% in low and middle-income countries, we find an infringement ratio which is more muted in India at about 5%. Finally, a regression-based examination suggests that prior firm presence in therapeutic markets and popularity of molecules positively impact the likelihood of sale of banned medicines in India. Our results are robust to alternative explanations and are substantiated with a theoretical set up examining firm trade-offs in the decision to infringe. India has recently been under the lens of the global access to medicines debate and our findings have important policy implications for global health.

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IIMA