This book constitutes the refereed proceedings of the 21st International Conference on Information Technologies and Mathematical Modelling. Queueing Theory and Applications, ITMM 2022, held in Karshi, Uzbekistan, during October 2529, 2022. The 19 full papers included in this book were carefully reviewed and selected from 89 submissions. The papers are devoted to new results in queueing theory and its applications. Its target audience includes specialists in probabilistic theory, random processes, mathematical modeling as well as engineers engaged in logical and technical design and operational management of data processing systems, communication, and computer networks.

Inhalt
Limit Theorems for the Positive Recurrent Q-process.- Numerical Analysis of Shortest Queue Problem for Time-Scale Queueing System with a Small Parameter.- Mathematical Modeling of Virtual Machine Life Cycle using Branching Renewal Process.- On Modeling a Section of a Single-Track Railway Network Based on Queuing Networks.- Asymptotic Analysis of a Multiserver Retrial Queue with Disasters in the Service Block.- Refined Limit Theorems for the Critical Continuous-Time Markov Branching Systems.- Retrial Queue MMPP/M/1 with Server Switching.- Account of Disasters in Analysis of Queueing Systems Modeled by the Quasi-Birth-and-Death-Process.- Retrial Queue with Two-Way Communication and Collisions.- Real Waiting Time in Single-server Resource Queue with Markovian Arrival Process.- Controlled Queueing Systems G/G/1 with Time Shift.- Analysis of Retrial Queueing System with Two-Way Communication in Different Scenarios using Simulation.- An Explicit Solution for an Inventory Model with Server Interruption and Retrials.- Asymptotic Analysis of the M/M/1/N1 Retrial System with Priority and Feedback.- Modelling of a MAP/PH(1),PH(2)/2 Production Inventory System with Multiple Servers and Production Vacations.- A Discrete Time Perishable Inventory System under (s, S) Policy and Age-Dependent-Requests.- N-Policy on a Retrial Inventory System.- Research of Dynamic RQ system M/M/1 with Unreliable Server.- Estimating the Distribution Function Using Parametric Methods in Informative Model of Random Censorship from Both Sides.