Server down time

[Arash-72]

I want to simulate a clinic in which a patient upon arrival visits a nurse for two minutes. Then visits the doctor for 3 minutes. Then again visits a nurse for 4 minutes and then leaves the clinic. However, the doctor right after visiting a patient doesn't take the next patient immediately and becomes unavailable to do some additional tasks (doing some documentation for that patient) for 1 minute. Such additional tasks don't have any effect on the leaving time of the current patient.
Assume that I have a total of two patients with arrival times of 0 and 3.
How can I include the doctor's unavailability time in the simulation in the correct way?

Here is the code that I have used clone().

env <- simmer()

patient_trajectory <- trajectory() %>%
  set_attribute("arr", function() {now(env)}) %>% 
  seize("nurse") %>%
  timeout(2) %>% 
  release("nurse") %>% 
  seize("Doctor") %>%
  set_attribute("doctor busy start", function() {now(env)}) %>% 
  timeout(3) %>%
  set_attribute("doctor busy end", function() {now(env)}) %>% 
  release("Doctor") %>% 
  clone(2, trajectory() %>% seize("Doctor") %>%
          set_attribute("doctor unavailable start", function() {now(env)}) %>% 
          timeout(1) %>%
          set_attribute("doctor unavailable end", function() {now(env)}) %>% 
          release("Doctor")) %>% 
  seize("nurse") %>%
  timeout(4) %>% 
  release("nurse") %>% 
  set_attribute("patient exit", function() {now(env)})

  
  
env %>% 
  add_resource("Doctor", capacity = 1) %>% 
  add_resource("nurse", capacity = Inf) 

env %>%
  add_generator("Patient", patient_trajectory, at(0, 3),mon = 2) 


env %>% run(until = 200)
env %>% get_mon_attributes()

But, as shown in the attached photo, the issue is the doctor starts visiting patient 2 before becoming unavailable after visiting patient 1.

Thank you so much for your time and attention in advance.

[Enchufa2]

This pattern is a "delayed release": the patient leaves, but the resource is still busy for some time. We implemented a helper for this in simmer.bricks, see delayed_release. (You can see that this helper uses clone internally, so you were headed in the right direction, but some pieces were missing in your solution).

[Arash-72]

delayed_release exactly does what I had in mind.
Thank you so much.

[Arash-72]

Hi.

I was wondering if you also know how to capture the time that a resource becomes available after a delayed release with attributes.
Unfortunately, I can't get it by using set_attribute("doctor unavailable end", function() {now(env)}) inside the trajectory like below:

...
delayed_release("Doctor") %>%
set_attribute("doctor unavailable end", function() {now(env)}) %>%
...

[Enchufa2]

This is how a delayed_release works: https://github.com/r-simmer/simmer.bricks/blob/bd348f1487deabe4c79a2efafaa22b1c041829cb/R/delayed_release.R#L51-L76. So you can just copy the function and rewrite it to add the attribute change in the proper place.

[Arash-72]

Thank you very much.