Open Access. Powered by Scholars. Published by Universities.®

Business Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 18 of 18

Full-Text Articles in Business

Predicting The Performance Of Queues: A Data Analytic Approach, Kum Khiong Yang, Cayirli Tugba, Mei Wan Low Dec 2016

Predicting The Performance Of Queues: A Data Analytic Approach, Kum Khiong Yang, Cayirli Tugba, Mei Wan Low

Research Collection Lee Kong Chian School Of Business

Existing models of multi-server queues with system transience and non-standard assumptions are either too complex or restricted in their assumptions to be used broadly in practice. This paper proposes using data analytics, combining computer simulation to generate the data and an advanced non-linear regression technique called the Alternating Conditional Expectation (ACE) to construct a set of easy-to-use equations to predict the performance of queues with a scheduled start and end time. Our results show that the equations can accurately predict the queue performance as a function of the number of servers, mean arrival load, session length and service time variability. …


Appointment Sequencing: Why The Smallest-Variance-First Rule May Not Be Optimal, Qingxia Kong, Chung-Yee Lee, Chung-Piaw Teo, Zhichao Zheng Dec 2016

Appointment Sequencing: Why The Smallest-Variance-First Rule May Not Be Optimal, Qingxia Kong, Chung-Yee Lee, Chung-Piaw Teo, Zhichao Zheng

Research Collection Lee Kong Chian School Of Business

We study the design of a healthcare appointment system with a single physician and a group of patients whose service durations are stochastic. The challenge is to find the optimal arrival sequence for a group of mixed patients such that the expected total cost of patient waiting time and physician overtime is minimized. While numerous simulation studies report that sequencing patients by increasing order of variance of service duration (Smallest-Variance-First or SVF rule) performs extremely well in many environments, analytical results on optimal sequencing are known only for two patients. In this paper, we shed light on why it is …


Least Squares Approximation To The Distribution Of Project Completion Times With Gaussian Uncertainty, Zhichao Zheng, Karthik Natarajan, Chung-Piaw Teo Nov 2016

Least Squares Approximation To The Distribution Of Project Completion Times With Gaussian Uncertainty, Zhichao Zheng, Karthik Natarajan, Chung-Piaw Teo

Research Collection Lee Kong Chian School Of Business

This paper is motivated by the following question: How to construct good approximation for the distribution of the solution value to linear optimization problem when the random objective coefficients follow a multivariate normal distribution? Using Stein’s Identity, we show that the least squares normal approximation of the random optimal value can be computed by estimating the persistency values of the corresponding optimization problem. We further extend our method to construct a least squares quadratic estimator to improve the accuracy of the approximation; in particular, to capture the skewness of the objective. Computational studies show that the new approach provides more …


Managing Emergency Department Crowding Through Improved Triaging And Resource Allocation, Kum Khiong Yang, Sean Shao Wei Lam, Joyce M. W. Low, Marcus Eng Hock Ong Sep 2016

Managing Emergency Department Crowding Through Improved Triaging And Resource Allocation, Kum Khiong Yang, Sean Shao Wei Lam, Joyce M. W. Low, Marcus Eng Hock Ong

Research Collection Lee Kong Chian School Of Business

Long waiting times in emergency departments (EDs) not only reduce patients’ perceived quality of care, but also increase crowding which can adversely affect patients’ outcomes. Waiting time has been found to affect patients’ outcomes and is closely associated with delays in the provision of ancillary services to ED patients by the diagnostic/treatment laboratories. The focus of this study is to improve the flow of ED patients by testing alternative triage processes and capacity of physicians, triage nurses and laboratories. Three alternative triage processes are examined for managing the flow of ED patients through shared and dedicated laboratories across different utilization …


The Impact Of The Potential Entry Of Copycats: Entry Conditions, Consumer Welfare, And Social Welfare, Sarah Y. Gao, Wei Shi Lim, Christopher Tang Aug 2016

The Impact Of The Potential Entry Of Copycats: Entry Conditions, Consumer Welfare, And Social Welfare, Sarah Y. Gao, Wei Shi Lim, Christopher Tang

Research Collection Lee Kong Chian School Of Business

This article examines the implications of the potential entry of a copycat who produces and sells a copycat (i.e., imitation) product that competes with the incumbent product. By analyzing a two-period dynamic noncooperative game between these two firms, we identify conditions under which the copycat can gain successful market entry. More importantly, we find that the potential entry of a copycat creates (implicit) pressure for the incumbent to lower its selling price; hence, it improves consumer welfare. Finally, we identify conditions under which the potential entry of a copycat can increase social welfare (i.e., consumer welfare and the profit of …


Can S'Pore Be An Icon For Service Productivity?, Arnoud De Meyer Apr 2016

Can S'Pore Be An Icon For Service Productivity?, Arnoud De Meyer

Research Collection Lee Kong Chian School Of Business

The traditional analysis tools or flexible work design deployed in manufacturing may be insufficient in giving a boost to services. For all practical purposes, there are only two ways to create more value per worker and stimulate growth, we need innovation or become more productive.


Ad Revenue Optimization In Live Broadcasting, Dana G. Popescu, Pascale Crama Apr 2016

Ad Revenue Optimization In Live Broadcasting, Dana G. Popescu, Pascale Crama

Research Collection Lee Kong Chian School Of Business

In live broadcasting, the break lengths available for commercials are not always fixed and known in advance (e.g., strategic and injury time-outs are of variable duration in live sports transmissions). Broadcasters actively manage their advertising revenue by jointly optimizing sales and scheduling policies. We characterize the optimal dynamic schedule in a simplified setting that incorporates stochastic break durations and advertisement lengths of 15 and 30 seconds. The optimal policy is a "greedy" look-ahead rule that accounts for the remaining number of breaks; in this setting, there is no value to perfect information at the scheduling stage, and hence knowing the …


A Framework For Evaluating Energy Sustainability Efforts In Maritime Terminal Operations, Kar Way Tan, Members Of Green Transformation Lab Apr 2016

A Framework For Evaluating Energy Sustainability Efforts In Maritime Terminal Operations, Kar Way Tan, Members Of Green Transformation Lab

Research Collection School Of Computing and Information Systems

Environmental sustainability at ports has been getting more attention from port operators and port regulators. GHG emissions associated with operations and search for clean energy sources are some issues that are continuously monitored and urgently addressed at leading ports across the world. Singapore port, one of the busiest in the world, is no exception. In the planning for the Singapore’s next generation port, this study helps to provide a framework to learn, evaluate and monitor sustainability initiatives in maritime terminal operations for Singapore and selected international ports.


Patrol Scheduling In An Urban Rail Network, Hoong Chuin Lau, Zhi Yuan, Aldy Gunawan Apr 2016

Patrol Scheduling In An Urban Rail Network, Hoong Chuin Lau, Zhi Yuan, Aldy Gunawan

Research Collection School Of Computing and Information Systems

This paper presents the problem of scheduling security teams to patrol a mass rapid transit rail network of a large urban city. The main objective of patrol scheduling is to deploy security teams to stations of the network at varying time periods subject to rostering as well as security-related constraints. We present several mathematical programming models for different variants of this problem. To generate randomized schedules on a regular basis, we propose injecting randomness by varying the start time and break time for each team as well as varying the visit frequency and visit time for each station according to …


Electricity Trading And Negative Prices: Storage Vs. Disposal, Yangfang (Helen) Zhou, Alan Scheller-Wolf, Nicola Secomandi, Stephen Smith Mar 2016

Electricity Trading And Negative Prices: Storage Vs. Disposal, Yangfang (Helen) Zhou, Alan Scheller-Wolf, Nicola Secomandi, Stephen Smith

Research Collection Lee Kong Chian School Of Business

Electricity cannot yet be stored on a large scale, but technological advances leading to cheaper and more efficient industrial batteries make grid-level storage of electricity surpluses a natural choice. Because electricity prices can be negative, it is unclear how the presence of negative prices might affect the storage policy structure known to be optimal when prices are only non-negative, or even how important it is to consider negative prices when managing an industrial battery. For fast storage (a storage facility that can both be fully emptied and filled up in one decision period), we show analytically that negative prices can …


Scenario-Based Simulation Game For Hospital Beds Capacity Planning In Singapore, Cheong, Michelle L. F., Li Siong Lim Mar 2016

Scenario-Based Simulation Game For Hospital Beds Capacity Planning In Singapore, Cheong, Michelle L. F., Li Siong Lim

Research Collection School Of Computing and Information Systems

A complete learning object with scenario-based simulation game and accompanying materials, which allows self-directed learners to learn and apply the theory, concepts and calculations for capacity planning, in the hospital beds capacity planning scenario in Singapore, was designed, developed and immplemented. It guides the learners through the key considerations for capacity planning, the computation of actual capacity needed, deciding the time for capacity increments, as well as the economies and diseconomies of scale when adding capacity. All the learnings are applied in a scenario where the learners make decision on how much and when to add hospital beds to existing …


Made In Singapore, Plugged Into The World, Arnoud Cyriel Leo De Meyer Mar 2016

Made In Singapore, Plugged Into The World, Arnoud Cyriel Leo De Meyer

Research Collection Lee Kong Chian School Of Business

Manufacturing in Singapore is not an outmoded sector. Instead, it is a job multiplier and can be a source of innovation as well as a vital way to plug the Republic into the global manufacturing network.


A Proactive Sampling Approach To Project Scheduling Under Uncertainty, Pradeep Varakantham, Na Fu, Hoong Chuin Lau Feb 2016

A Proactive Sampling Approach To Project Scheduling Under Uncertainty, Pradeep Varakantham, Na Fu, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

Uncertainty in activity durations is a key characteristic of many real world scheduling problems in manufacturing, logistics and project management. RCPSP/max with durational uncertainty is a general model that can be used to represent durational uncertainty in a wide variety of scheduling problems where there exist resource constraints. However, computing schedules or execution strategies for RCPSP/max with durational uncertainty is NP-hard and hence we focus on providing approximation methods in this paper. We pro- vide a principled approximation approach based on Sample Average Approximation (SAA) to compute proactive schedules for RCPSP/max with durational uncertainty. We further contribute an extension to …


Achieving Stable And Fair Profit Allocation With Minimum Subsidy In Collaborative Logistics, Lucas Agussurja, Hoong Chuin Lau, Shih-Fen Cheng Feb 2016

Achieving Stable And Fair Profit Allocation With Minimum Subsidy In Collaborative Logistics, Lucas Agussurja, Hoong Chuin Lau, Shih-Fen Cheng

Research Collection School Of Computing and Information Systems

With the advent of e-commerce, logistics providers are faced with the challenge of handling fluctuating and sparsely distributed demand, which raises their operational costs significantly. As a result, horizontal cooperation are gaining momentum around the world. One of the major impediments, however, is the lack of stable and fair profit sharing mechanism. In this paper, we address this problem using the framework of computational cooperative games. We first present cooperative vehicle routing game as a model for collaborative logistics operations. Using the axioms of Shapley value as the conditions for fairness, we show that a stable, fair and budget balanced …


Cost-Reducing Innovation And The Role Of Patent Intermediaries In Increasing Market Efficiency, Anupam Agrawal, Shantanu Bhattacharya, Sameer Hasija Feb 2016

Cost-Reducing Innovation And The Role Of Patent Intermediaries In Increasing Market Efficiency, Anupam Agrawal, Shantanu Bhattacharya, Sameer Hasija

Research Collection Lee Kong Chian School Of Business

Patent intermediaries have gained importance as non-practicing entities in the innovation domain, buying innovations from an external provider and then licensing them to practicing firms. In this study, we analyze the competition between two identical incumbent firms and a patent intermediary for the acquisition and licensing of a cost-reducing innovation developed by an external innovator. We show that the outcome of the IP acquisition and licensing game critically depends on the degree of the cost-reducing innovation. Patent intermediaries win IP rights in patent markets if the innovation is incremental. They also win the IP rights when the innovation is moderate …


Delayering The Global Production Network Into Congruent Subnetworks, Kasra Ferdows, Ann Vereecke, Arnoud De Meyer Jan 2016

Delayering The Global Production Network Into Congruent Subnetworks, Kasra Ferdows, Ann Vereecke, Arnoud De Meyer

Research Collection Lee Kong Chian School Of Business

The literature in operations management has not kept up with the growing complexity of and opportunities offered by global production networks. Managers need new tools to cope with this complexity. We propose one that is based on a model that delayers the global plant network into a set of subnetworks on the basis of complexity and proprietary information in the products they produce and production processes they use to produce them. This allows examining whether each subnetwork is congruent i.e., has an appropriate manufacturing mission and the competencies that it would need to carry it out. We apply this tool …


Enabling Carrier Collaboration Via Order Sharing Double Auction: A Singapore Urban Logistics Perspective, Handoko Stephanus Daniel, Hoong Chuin Lau Jan 2016

Enabling Carrier Collaboration Via Order Sharing Double Auction: A Singapore Urban Logistics Perspective, Handoko Stephanus Daniel, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

A recent exploratory study on the collaborative urban logistics in Singapore suggests that cost reduction and privacy preservation are two main drivers that would motivate the participation of carriers in consolidating their last mile deliveries. With Singapore's mild restrictions on the vehicle types or the time windows for the last-mile delivery, we believe that with proper technology in place, an Urban Consolidation Center like the Tenjin Joint Distribution System in Fukuoka Japan may be implemented to achieve cost reduction with some degree of privacy preservation. Participating carriers keep their respective private orders and have the option to get their remaining …


The Impact Of Budget Constraints On Flexible Vs. Dedicated Technology Choice, Onur Boyabatli, Tiecheng Leng, L. Beril Toktay Jan 2016

The Impact Of Budget Constraints On Flexible Vs. Dedicated Technology Choice, Onur Boyabatli, Tiecheng Leng, L. Beril Toktay

Research Collection Lee Kong Chian School Of Business

This paper studies the flexible versus dedicated technology choice and capacity investment decisions of a multiproduct firm under demand uncertainty in the presence of budget constraints. The firm operates under a capital budget for financing the capacity investment, and an operating budget, which is uncertain in the capacity investment stage, for financing the production. We investigate how the tightening of the capital budget and a lower financial flexibility in the production stage (the likelihood of having a sufficient operating budget) shape the optimal technology choice. We find that the dominant regime is one where dedicated technology should be adopted for …