R erlang

Rewrote the ExcelVBA code from Erlang.xlsx sheet for call center calculations.

ErlangB <- function(servers,intensititys)

{   

  z <- if(servers < 0) 0

  z <- if(intensititys < 0) 0

  MaxIterate <- as.integer(servers)

  Val <- intensititys

  Last <- 1    

  for( i in 1:MaxIterate)

  { z <- (Val * Last) / (i + (Val * Last))

  Last <- z  

  }

  z<-ifelse(z<0,0,z)

  z<-ifelse(z>1,1,z)

  print(z)

  z

}

ErlangC <- function(server,intensitity)

{  

  x <- if(server < 0) 0

  x <- if(intensitity < 0) 0   

  B <- ErlangB(servers=server,intensititys=intensitity)

  C <- B / (((intensitity / server) * B) + (1 - (intensitity / server)))    

  C<-ifelse(C<0,0,C)

  C<-ifelse(C>1,1,C)

  x <- C

  print(x)

  x

}

ErlangASA <- function(Agents,CPH,AHT)

{ BirthRate <- CPH

DeathRate <- 3600 / AHT

TrafficRate <- BirthRate / DeathRate

Server <- Agents

Utilisation <- TrafficRate / Server        

Utilisation <-ifelse(Utilisation>=1,.99,Utilisation)

print(BirthRate)

print(DeathRate)

print(TrafficRate)

print(Agents)

print(Utilisation)

C <-ErlangC(server=Agents,intensitity=TrafficRate)

AnswerTime <- C / (Server * DeathRate * (1 - Utilisation))

AveAnswer <- as.integer(AnswerTime * 3600 +.5)

ASA <- AveAnswer      

ASA

print(ASA)

}

output <- ErlangASA(Agents=50,CPH=300,AHT=924)

print(output)