High-enrollment Mega-Open Universities—institutions delivering open and distance learning (ODL) to student bodies exceeding 100,000 learners—face persistent structural trade-offs between maintaining physically decentralized regional study center networks and deploying centralized digital student support systems. While regional study centers foster valuable localized counseling, peer community, and academic contact, maintaining distributed brick-and-mortar facilities incurs substantial fixed overhead costs. Conversely, centralized online portals and automated query ticketing systems fundamentally alter institutional cost functions, converting heavy fixed administrative liabilities into scalable variable tutoring operations. This systematic literature review evaluates the operational and economic outcomes of traditional decentralized study center models versus automated, digital, and centralized virtual learner support services within Mega-Open Universities using the CIMO (Context, Intervention, Mechanism, Outcome) framework.

We synthesized peer-reviewed empirical research articles and scholarly book chapters published on or before December 31, 2020, focusing on distance and open higher education institutions. Eligible studies evaluated learner support cost structures, resource allocation matrices, query resolution speeds, or longitudinal student retention, while non-empirical essays, post-2020 publications, and residential education settings were systematically excluded. Comprehensive searches across five multidisciplinary academic databases (Scopus, Web of Science Core Collection, EBSCOhost ERIC and Business Source Premier, ProQuest Education Database, and JSTOR Arts & Sciences), supplemented by forward and backward citation chaining, retrieved 2,788 records. Following automated and manual deduplication (874 removed) and dual-stage title/abstract screening, 168 full-text reports were appraised, yielding a final synthesized corpus of 32 empirical studies meeting all eligibility criteria. Methodological quality and risk of bias were systematically appraised using the Mixed Methods Appraisal Tool (MMAT) 2018 edition, and evidence certainty was evaluated via the GRADE and GRADE-CERQual frameworks.

The synthesized evidence demonstrates that transitioning routine administrative support from physical regional centers to centralized virtual helpdesks produces substantial per-student unit cost reductions (ranging from 12% to 35% below conventional campus delivery models) once institutional enrollment thresholds surpass 100,000 learners. Automated ticketing systems and asynchronous virtual portals compress student query and grievance turnaround times from several weeks to under 4 hours, generating critical administrative economies of scale. Concurrently, proactive telephonic and electronic tutoring interventions yield statistically significant gains in course completion (8.2% to 12.4%) and positive institutional returns on investment, recovering up to £3.20 in preserved tuition revenue per £1.00 invested. Although substantial methodological heterogeneity across the included corpus precluded statistical meta-analysis, the findings indicate that distance education executives and policymakers must avoid digital centralization solely as an austerity measure. Instead, institutions should adopt a hybridized resource matrix that routes administrative transactions through centralized automated portals while concentrating variable funding on proactive, localized tutor-student engagement.