Managing complex service operations requires a comprehensive understanding of the fundamental dynamics and intricacies that affect the performance of service firms. This study is a review of the critical literature on how quality management, customer inputs, and operational complexity are interrelated and their respective influence on the delivery of knowledge-based service operations. Research propositions are developed to illustrate the key relationships among concepts and basic components of service quality, indispensable customer inputs, and prime sources of operational complexity. The study identifies two dimensions of quality; process quality and output quality and four categories of customer inputs; physical presence, task performance, material belongings, and information and knowledge. The study pinpoints four sources of operational complexity; complicatedness, uncertainty, interrelatedness, and multiplicity. A conceptual model is developed as a foundation for future research, particularly in service delivery systems, customer evaluation tools, and complex systems. The study extends knowledge of how knowledge-based service operations can enhance productivity by managing quality, customer inputs, and operational complexity.