Investigating the Influence of Queuing Theory Parameters on Customer Satisfaction at ZANACO: The Mediating Role of Customer Waiting Time

Abstract

This study examines the influence of queuing theory parameters on customer satisfaction through the mediating role of customer waiting time at Zanaco Cairo Road Branch in Lusaka, Zambia. In retail banking, service efficiency remains a critical determinant of customer satisfaction; however, prolonged waiting time persists as a significant operational challenge, particularly in high-traffic branch environments within developing economies. Despite advancements in digital banking and queue management systems, congestion in physical banking halls continues to undermine service experience. This study addresses this gap by integrating queuing theory with expectation–disconfirmation theory to provide a mechanism-based explanation of how operational system characteristics translate into customer satisfaction outcomes. Guided by three objectives, the study examines: (i) the effect of queuing theory parameters on customer waiting time, (ii) the effect of waiting time on customer satisfaction, and (iii) the operational factors influencing both waiting time and satisfaction. Anchored in a critical realist philosophy, the study adopts a sequential explanatory mixed-methods design. Quantitative data were collected through 320 structured observations and 53 customer questionnaires, while qualitative insights were derived from 15 semi-structured staff interviews to explain underlying operational mechanisms. Findings indicate that customer arrivals are heavily concentrated during peak morning hours (08:30–09:30), resulting in demand–capacity imbalances and system congestion. The average waiting time of approximately 28 minutes significantly exceeds accepted service benchmarks. Regression analysis demonstrates that queuing theory parameters significantly predict waiting time (R² = 0.507, p < 0.001), while waiting time exerts a strong negative effect on customer satisfaction (β = -0.65, p < 0.001), confirming its mediating role. Qualitative findings further reveal that staffing constraints, transaction complexity, and system inefficiencies constitute key generative mechanisms driving delays. The study concludes that customer waiting time is the critical transmission mechanism through which queuing system design influences customer satisfaction. It recommends dynamic capacity alignment and process optimization to enhance service efficiency and customer experience in retail banking.