Call Center Staffing with Simulation and Cutting Plane Methods

We present an iterative cutting plane method for minimizing staffing costs in a service system subject to satisfying acceptable service level requirements over multiple time periods. We assume that the service level cannot be easily computed, and instead is evaluated using simulation. The simulation uses the method of common random numbers, so that the same sequence of random phenomena is observed when evaluating different staffing plans. In other words, we solve a sample average approximation problem. We establish convergence of the cutting plane method on a given sample average approximation. We also establish both convergence, and the rate of convergence, of the solutions to the sample average approximation to solutions of the original problem as the sample size increases. The cutting plane method relies on the service level functions being concave in the number of servers. We show how to verify this requirement as our algorithm proceeds. A numerical example showcases the properties of our method, and sheds light on when the concavity requirement can be expected to hold.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44119/1/10479_2004_Article_5255891.pd

Sistem Penyusunan Kepegawaian Pada Manajemen Call Center Dengan Multi-class Pelanggan Dan Multi-pool Server

Penelitian ini mempertimbangkan suatu model call center dari pengarahan berbasis ketrampilan. Model ini merupakan server yang bersifat homogen dan heterogen dengan sejumlah aliran masuk dan sejumlah kelompok agen, dengan tingkat kedatangan seketika yang diperbolehkan bersifat tergantung dengan waktu (time-dependent) dan bersifat stokastik. Pelanggan yang tidak sabar menunggu untuk dilayani agen kemungkinan akan meninggalkan antrian dan terdapat biaya hukuman yang berhubungan dengan penundaan tersebut. Metoda penyusunan kepegawaian yang diajukan mengoptimalkan perimbangan antara biaya personel dan hukuman penundaan dengan melakukan pengembangan dan penjelasan suatu metoda praktis untuk mengukur jumlah kelompok agen. Dengan menggunakan suatu model stokastik fluida, metoda ini mereduksi permasalahan dalam penyusunan kepegawaian ke bentuk newsvendor problem, yang dapat dipecahkan secara numerik melalui suatu kombinasi linear programming dan simulasi Monte Carlo. Hasil penelitian dan analisa yang diperoleh, dimana dalam semua kasus untuk ukuran kelompok yang diperoleh dari hasil simulasi hampir mendekati optimal dengan hasil dari metode pendekatan yang diusulkan, sekitar 2%-3%.

Centralising the Admission Process in a German Hospital

The admission process is the first part of a hospital stay for all in- and outpatients. For the hospital, it is a critical part as all the necessary data must be stored in the hospital information system and all legal documents have to be signed in order to guarantee the best possible treatment and efficient logistics. In this paper, we focus on the admission process in a German hospital. As the admission of a patient, especially informing and advising him, is very time consuming, the hospital aims at installing a digital admission process. The first important step towards this goal is pooling the current decentralised patient admission in one new building. Using a simulation, we determine efficient staffing levels and rosters for the centralised admission and analyse the expected waiting times for the patients. In addition, we outline potential steps towards a digital patient admission process

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

Capacity planning with working time accounts in services

This paper presents, formalises and classifies working time accounts (WTA’s), means of achieving flexible production capacity through the flexible organization of working time. We propose linear programming models to plan working time, using WTA, at companies in service industry. A computational experiment shows that the models can be solves for any planning problems of reasonable size

DCPP/POLYGAIT Inventory Control System

This report discusses a proposed system to improve upon inventory management issues experienced in the M&TE Tool room for the PG&E Diablo Canyon Power plant. Effective inventory tracking and management is an important characteristic of any organization handling physical assets, and without the proper system in place, companies may lose expensive items and waste time by not having equipment available when needed. The tool room is experiencing inventory shrinkage of M&TE equipment nearing 100,000 per year largely because of an inefficient checkout system that fails to keep employees accountable for the tools they check out. Even more costly than the shrinkage of inventory is the expense of downtime incurred by not having a tool ready when needed. Two main issues with the current system were identified as the reasons for the shrinkage and lack of accountability: 1 when no tool clerk is on staff, mainly nights and weekends, an unreliable paper-method for checkout is used, and 2, employees are not held responsible for checking their tools back in, resulting in tools being handed-off outside of the tool room. To combat these problems, a self-checkout/check-in system was developed, eliminating the need for the paper system, requiring an employee login for returning tools, and reducing the total number of steps in the process by 36%. PG&E was also interested in using RFID (Radio Frequency Identification) technology to further increase accountability and improve the tracking of tools in and out of the tool room. A working proof-of-concept model was designed, built, and tested at Cal Poly’s POLYGAIT Laboratory along with recommendations for a potential implementation at PG&E. The results of the portal testing indicate that the best RFID tags for larger items include the Confidex Ironside Slim or Xerafy Cargo Trak tags while the Confidex Captura G2XM should be used for cabled probes. In addition, a maximum of six tools should be carried through the portal at a single time. An economic analysis for the proposed RFID system with revised checkout was performed along with two other alternatives: an increase in staffing on nights and weekends with the revised checkout and regular staffing with the revised checkout. All three alternatives were compared to the current state, which includes regular staffing without the revised checkout. The results of the economic analysis suggest that the RFID system paired with the revised checkout provides the lowest total cost solution, with a payback period of 0.046 years and a cumulative four-year return of 1,442,914.00. The second total lowest cost solution, which is the revised checkout method alone without an RFID system or increase in staffing, provides the fastest payback period of all the alternatives, in 0.019 years, but provides less of a return on an investment than when paired with the RFID system

Simulation analysis of resident and attending physician teaching methods at Kosair Children\u27s Hospital.

The Kosair Children\u27s Hospital, located in Louisville, Kentucky, is the only children\u27s hospital in the state. Recently, the hospital\u27s emergency department has developed concerns with patient satisfaction. Patients have experienced excessive amounts of time to get through the emergency department resulting in low satisfaction. Hence, this research assesses the patient\u27s time in the emergency department through the use of a computer simulation. Specifically, a study on the teaching methods for the resident physicians was examined to determine if there were different approaches that could be implemented to improve a patient\u27s time in the emergency department. Findings showed that the teaching method of having an attending physician with the resident physician whenever they visit a patient was the best teaching method. This teaching method only showed significant improvement if the number of attending physicians was adjusted from two to three starting at 3:00 PM until 11:00 PM. These changes resulted in a 28% reduction of total time in the system for patients. These results provide a starting point for Kosair to make improvements to their emergency department; however, there are areas that warrant further research

Reescalonamento de equipas de atendimento permanente : caso prático em telecomunicações

Mestrado em Decisão Económica e EmpresarialNuma equipa de atendimento permanente com um escalonamento pré-definido, qualquer motivo de ausência de um colaborador (baixa, formação, férias, etc.) provoca uma cadeia de alterações nos horários já atribuídos. Atualmente, a forma de ultrapassar o problema consiste em afetar um elemento da equipa à árdua tarefa de realocar os colaboradores aos horários ainda não atribuídos, de forma manual. Este projeto pretende ultrapassar o problema através do desenvolvimento de uma heurística de reescalonamento que produza uma nova programação de horários. Inicialmente recorre-se ao VBA para reproduzir o escalonamento pré-definido pela empresa. Após o escalonamento, é programada uma heurística com o objetivo de minimizar o impacto no escalonamento inicial face a imprevistos. O resultado consiste num novo escalonamento tendo em conta restrições associadas a horários imprescindíveis e às limitações inerentes aos contratos laborais de cada colaborador.In a permanent attendance team with a predefined schedule, any reason of absence given by an employee (illness, professional qualification, vacation, etc.) causes a chain of changes in the schedules already assigned. Now, the way to overcome the problem is to entrust a team member the arduous task of relocating employees to schedules not assigned yet, has to be done manually. This project aims to overcome the problem by developing a rescheduling heuristic that produces a new shifting plan. Initially, resorts to VBA which reproduce the default timetable of the company. After, is defined a heuristic in order to minimize the impact, in case of unexpected problems, in the initial stagger which will result in a new calendar, following all the restrictions associated with crucial schedules and inherent limitations in each employee's contract