Hi, I'm trying to write codes for a loop to simulate Arrivals and Departures. There's only one server (M/M/1) and it is a FCFS. So if someone arrives when the server is busy, then they have to wait for the server to be free. data have;
input id time_of_arrival service_time;
datalines;
1 1.5 2
2 2 1
3 3.5 2
4 8 1
5 10 2
6 12 1
7 13 2
8 14 2
9 16 3
run;
data have;
set have;
time_of_leaving = time_of_arrival + service_time;
lag_time_of_leaving = lag(time_of_leaving);
if lag_time_of_leaving > time_of_arrival then flag = 1; else flag = 0;
run; I thought about creating another variable = 0 (flag2) and loop until flag = flag2 (see following code - it added it before the run; command in the previous code). However, the program has been running for the past hour and my initial thought is that there must be a more efficient way of doing it. flag2 = 0;
do until (flag = flag2);
if flag = 1 then time_of_leaving = lag_time_of_leaving + service_time;
lag_time_of_leaving = lag(time_of_leaving);
if lag_time_of_leaving > time_of_arrival then flag = 1; else flag = 0;
end; In the end, I'd like for the results to be as followed id time_of_arrival service_time time_of_leaving 1 1.5 2 3.5 2 2 1 4.5 (server is free at 3.5 + service_time of 1) 3 3.5 2 6.5 4 8 1 9 5 10 2 12 6 12 1 13 7 13 2 15 8 14 2 17 9 16 3 20 Thank you in advance for your help
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