Managing Trade-Offs in Call Center Agent Scheduling: Methodology and Case Study

This paper develops a flexible and tractable scheduling methodology that produces near-optimal call center agent schedules while taking into account the costs associated with customer waiting time, customer abandonment, and call center agents. Our methodology combines integer programming (to find a desirable staffing plan for a given total number of agents) and simulation modeling (to evaluate the weekly costs of a given staffing plan). We describe the advantages of this approach over the traditional scheduling method, and test both methods by building schedules based on actual demand and shift data from an actual call center operated by Expedia.com under a variety of cost scenarios. The new scheduling approach not only out-performs the traditional staffing approach in all scenarios examined, it reduces total weekly costs of the call center\u27s existing agent schedule by 8-25%, depending on the scenario

Performance Measures for Service Systems with a Random Arrival Rate

It is commonly assumed that the arrival process of customers to a service stystem is a nonhomogeneous Poisson process. Call center data often refute this assumption, and several authors have postulated a doubly-stochastic Poisson process for arrivals instead. We develop approximations for bothe the long-run fraction of calls answered quickly, and the distribution of the fraction of calls answered quickly within a short period. We also perform a computational study to evaluate the approximations and improve our understanding of such systems

Data Science: Past, Present, and Future

Data science is a growing in popularity. Vijay Mehrotra chronicles the field from its inception in the early days of technology to new and emerging areas in technology and management

Towards Evaluating the Quality of a Spreadsheet: The Case of the Analytical Spreadsheet Model

We consider the challenge of creating guidelines to evaluate the quality of a spreadsheet model. We suggest four principles. First, state the domain-the spreadsheets to which the guidelines apply. Second, distinguish between the process by which a spreadsheet is constructed from the resulting spreadsheet artifact. Third, guidelines should be written in terms of the artifact, independent of the process. Fourth, the meaning of "quality" must be defined. We illustrate these principles with an example. We define the domain of "analytical spreadsheet models", which are used in business, finance, engineering, and science. We propose for discussion a framework and terminology for evaluating the quality of analytical spreadsheet models. This framework categorizes and generalizes the findings of previous work on the more narrow domain of financial spreadsheet models. We suggest that the ultimate goal is a set of guidelines for an evaluator, and a checklist for a developer.Comment: Proc. European Spreadsheet Risks Int. Grp. (EuSpRIG) 2011 ISBN 978-0-9566256-9-

A Use Case-Engineering Resources Taxonomy for Analytical Spreadsheet Models

This paper presents a taxonomy for analytical spreadsheet models. It considers both the use case that a spreadsheet is meant to serve, and the engineering resources devoted to its development. We extend a previous three-type taxonomy, to identify nine types of spreadsheet models, that encompass the many analytical spreadsheet models seen in the literature. We connect disparate research literature to distinguish between an "analytical solution" and an "industrial-quality analytical spreadsheet model". We explore the nature of each of the nine types, propose definitions for some, relate them to the literature, and hypothesize on how they might arise. The taxonomy aids in identifying where various spreadsheet development guidelines are most useful, provides a lens for viewing spreadsheet errors and risk, and offers a structure for understanding how spreadsheets change over time. This taxonomy opens the door to many interesting research questions, including refinements to itself.Comment: 13 Pages, 7 Figures, 2 Table

Improving Call Center Operations Using Performance-Based Routing Strategies

The article presents a simulation study of performance-based call routing strategies using a variety of routing rules based on historic data such as average handling time and first call resolution rate. We demonstrate the relative benefits of various performance-based call routing strategies using actual data from a financial call center. In particular, our modeling results indicate that call routing based on adjusted average handle time (AAHT) and z-scores of AAHT are two strategies that can substantially improve overall call center performance and customer satisfaction

Intelligent Procedures for Intra-Day Updating of Call Center Agent Schedules

For nearly all call centers, agent schedules are typically created several days or weeks prior to the time that agents report to work. After schedules are created, call center resource managers receive additional information that can affect forecasted workload and resource availability. In particular, there is significant evidence, both among practitioners and in the research literature, suggesting that actual call arrival volumes early in a scheduling period (typically an individual day or week) can provide valuable information about the call arrival pattern later in the same scheduling period. In this paper, we develop a flexible and powerful heuristic framework for managers to make intra-day resource adjustment decisions that take into account updated call forecasts, updated agent requirements, existing agent schedules, agents’ schedule flexibility, and associated incremental labor costs. We demonstrate the value of this methodology in managing the trade-off between labor costs and service levels to best meet variable rates of demand for service, using data from an actual call center

Two port laparoscopic ventral hernia mesh repair: An innovative technical advancement

AbstractVentral hernia is a common surgical problem. The traditional open surgical repair has the disadvantage of excessive morbidity, long hospital stay and high recurrence rates. Laparoscopic ventral hernia repair (LVHR) is gaining acceptance but there is no standardized technique for the repair of these hernias. We have introduced an innovative technique of 2-port laparoscopic mesh repair for ventral and incisional hernias.Between January 2002 and September 2008, 168 patients underwent the 2-port repair of ventral hernias at our institution, with Bard polypropylene mesh in 162 cases and Gore-tex expanded polytetrafloroethylene mesh in 6 patients. The average size of the defects was 10.2 cm (6.6–24.8 cm). Mean operating time was 61.4 min (48–102 min). The mean post-operative hospital stay was 1.2 days. Prolonged ileus over one day occurred in 22 patients while 6 patients had urinary retention in the post-operative period. There were 6 recurrences (3.94%) in the mean follow up period of 42 months (6–62 months). Seroma formation occurred in 5.3% cases but all of them subsided within 6 weeks without any active intervention.In conclusion we recommend that the 2-port LVHR is a technically sound procedure which is less invasive and with comparable complication rates to the 3 or 4 port hernia repair

Lessons from Mission-Critical Spreadsheets

We present eighteen examples of mission-critical spreadsheets used by diverse people and organizations for application software development, financial risk management, executive information systems, sales and marketing business processes, business operations, and complex analytics. We argue the spreadsheet is a Rapid Development Language, an Integrated Development Environment, and a Fourth Generation Language, and has unusual challenges regarding source code protection. We note that intentional spreadsheet applications are largely absent from the error literature. We explain why people might prefer a spreadsheet to an application developed by the IT department, and show how some spreadsheet programmers choose to avoid--or do not have--an IT department. We find that 1) Spreadsheets are widely used for mission-critical functions; 2) Spreadsheets are an effective application development platform; 3) There is diversity of development skill in creators of mission-critical spreadsheets; 4) Sophisticated programmers sometimes choose spreadsheets over other languages; 5) Spreadsheets are amenable to formal development practices, but such practices seem rare; 6) Spreadsheets play a central role in the evolution of business processes and work systems; and 7) Spreadsheets are a source of accidental legacy systems . We provide the Skill-User Programming Paradigm to help interpret and explain our observations. We conclude that spreadsheets are vitally important to business, and merit sustained research to discover techniques to enhance quality, productivity, and maintainability