[Paper Review] A practice-oriented overview of call center workforce planning

Ger Koole, Siqiao Li|arXiv (Cornell University)|Jan 21, 2021

Advanced Queuing Theory Analysis98 references4 citations

TL;DR

This paper presents a practice-oriented overview of call center workforce planning, evaluating common methods for their quality and theoretical applicability. It emphasizes flexible staffing, automation, and integrated WFM processes to balance service levels, agent satisfaction, and cost efficiency, with key contributions in multi-skilled staffing, real-time decision support, and operational design principles.

ABSTRACT

We give an overview of the practice and science of call center workforce planning, where we evaluate the commonly used methods by their quality and the theory by its applicability. As such this paper is useful for developers and consultants interested in the background and advanced methodology of workforce management, and for researchers interested in practically relevant science.

Motivation & Objective

• To bridge the gap between academic workforce management (WFM) theory and real-world call center practice.
• To evaluate commonly used WFM methods based on their practical quality and theoretical applicability.
• To guide developers, consultants, and researchers in implementing advanced, operationally relevant WFM methodologies.
• To highlight the importance of flexibility, automation, and integrated decision-making in modern contact centers.
• To provide design principles that align WFM with broader organizational goals, including service level agreements (SLAs), fairness, and cost control.

Proposed method

• Uses a framework of three core WFM processes: long-term budget planning, tactical capacity planning, and short-term operational scheduling.
• Integrates forecasting as the foundation for all WFM steps, with emphasis on updating forecasts for intra-day accuracy.
• Proposes automated decision-making tools that use real-time SLA predictions to support scheduling and routing decisions.
• Emphasizes multi-skilled agent utilization and flexible shift structures to reduce overcapacity and improve responsiveness.
• Applies simulation and analytical modeling to evaluate alternative architectures, such as SBR (skills-based routing) and back-office support.
• Recommends using predictive routing and call-back systems to smooth demand and reduce abandonment rates.

Experimental results

Research questions

• RQ1 How can workforce planning methods be evaluated for both practical quality and theoretical soundness in real call center environments?
• RQ2 What role does agent flexibility—across skills, shifts, and roles—play in reducing overstaffing and improving service levels?
• RQ3 How can real-time forecasting and automated decision systems improve intra-day scheduling and routing decisions?
• RQ4 What are the operational and financial trade-offs between volume-based and capacity-based outsourcing contracts in contact centers?
• RQ5 How do design choices—such as shift structures, channel integration, and SLA enforcement—affect long-term WFM performance and cost efficiency?

Key findings

• Flexibility in staffing—through part-time shifts, multi-skilled agents, and back-office support—provides significant benefits with decreasing returns, making it more effective to have multiple small sources of flexibility than one large one.
• Automated decision-making systems that predict SLA compliance in real time can significantly improve scheduling efficiency and reduce reliance on manual intra-day interventions.
• Call-back systems and predictive dialing help smooth demand fluctuations, reducing abandonment rates and improving resource utilization.
• Multi-skilled staffing models that route calls to the least occupied team improve both service efficiency and team motivation through performance transparency.
• Outsourcing contracts must be selected based on operating environment and cost-revenue structures, as neither volume-based nor capacity-based models are universally optimal.
• WFM is often excluded from early design decisions, but integrating WFM considerations early—such as on AHT, opening hours, or channel design—can prevent costly overstaffing or service level breaches.