Σύγκριση μεθόδων

	Μοντέλο Ουράς M/M/c: Μοντέλο Ουράς Πολλαπλών Εξυπηρετητών	Μοντέλο Erlang C
Πεδίο	Επιχειρησιακή Έρευνα	Επιχειρησιακή Έρευνα
Οικογένεια	Regression model	Regression model
Έτος προέλευσης	1998	1981
Δημιουργός	Queueing-theory tradition; Gross & Harris	Agner Krarup Erlang; Cooper
Τύπος	Multi-server Markovian queueing model	Steady-state queueing model
Θεμελιώδης πηγή	Gross, D., & Harris, C. M. (1998). Fundamentals of Queueing Theory (3rd ed.). Wiley. ISBN: 978-0-471-17083-9	Cooper, R. B. (1981). Introduction to Queueing Theory (2nd ed.). North-Holland. ISBN: 978-0-444-00379-7
Εναλλακτικές ονομασίες	Multi-Server Erlang Queue, c-Server Markovian Queue, Erlang-C Queue, Çok Sunuculu M/M/c Kuyruğu	M/M/c Queue, Multi-Server Queueing Model, Erlang Delay Formula, Erlang-C Bekleme Modeli
Συναφείς	3	3
Σύνοψη	The M/M/c queue is a multi-server stochastic model in which customers arrive according to a Poisson process at rate λ, are served by c identical servers each with exponentially distributed service times at rate μ, and wait in a single common queue when all servers are busy. Systematized within classical queueing theory and thoroughly treated by Gross and Harris (1998), it extends the simpler M/M/1 model to settings with parallel servers, making it the foundational tool for capacity planning in service systems.	The Erlang C model is a steady-state queueing formula that determines the probability a customer must wait before being served in a system with c parallel servers, Poisson arrivals at rate lambda, and exponentially distributed service times. Originally developed by Danish engineer Agner Krarup Erlang in the early twentieth century for telephone exchange design, and formalized in the queueing theory literature by Cooper (1981), it remains the canonical staffing model for call centers and service operations worldwide.