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pythonsimulationsimpy

What happens if I using 'env.process()' whenever I need it?


I'd like to have a bed cleaner only when necessary. The error does not occur as shown in the code below, but the result is not accurate. Increasing or decreasing the number of cleaner should change the results, but the result is the same regardless of the change in the number of cleaner. Maybe I can guess, whenever I use 'env.process()' the "self.bed_cleaner" is reset. So, cleaner is always idle... but I'm not sure. What do you think I don't understand? Please help me I can experiment properly.

import simpy
import random

class Pre_define:
    ed_bed_cleaning_request = True

class Patients:
    def __init__(self, p_id):
        self.id = p_id
        self.edbed_name = ""
        self.iubed_name = ""
        self.admission_decision = ""
        self.wtime_bed_NotClean = float("nan")
    def admin_decision(self):
        if (self.id % 2) == 0: # even dis, else IU 50%
            self.admission_decision = "DIS"
        else:
            self.admission_decision = "IU"
        return self.admission_decision

class Model:
    def __init__(self, run_number):
        self.env = simpy.Environment()
        self.pt_ed_q = simpy.Store(self.env )
        self.pt_counter = 0
        self.tg = simpy.Resource(self.env, capacity = 4)
        self.physician = simpy.Resource(self.env, capacity = 4)
        self.edbed_clean = simpy.Store(self.env, capacity = 4)
        self.iubed_clean = simpy.Store(self.env, capacity = 4)
        self.bed_dirty = simpy.Store(self.env, capacity = 8)
        self.bed_cleaner = simpy.Resource(self.env, capacity = 1)
    def generate_beds(self):
        for i in range(4):
            yield self.env.timeout(0)
            yield self.edbed_clean.put(f'edbed{i}')
            yield self.iubed_clean.put(f'iubed{i}')
    def generate_pt_arrivals(self):
        while True:
            pt = Patients(self.pt_counter)
            yield self.env.timeout(5)
            self.env.process(self.process(pt))
            self.pt_counter += 1            
    def clean_beds_process(self, pt):
        bed = yield self.bed_dirty.get()
        while True:
            if (Pre_define.ed_bed_cleaning_request == True and bed[:2] == 'ed') or (Pre_define.ed_bed_cleaning_request == False and bed[:2] == 'iu'):
                with self.bed_cleaner.request() as bedreq:
                    yield bedreq
                yield self.env.timeout(30)
                if bed[:2] == 'ed':
                    yield self.edbed_clean.put(bed)
                else:
                    yield self.iubed_clean.put(bed)
                break
            elif (Pre_define.ed_bed_cleaning_request == False and bed[:2] == 'ed') or (Pre_define.ed_bed_cleaning_request == True and bed[:2] == 'iu'):
                with self.bed_cleaner.request() as bedreq:
                    yield bedreq
                yield self.env.timeout(30)
                if bed[:2] == 'ed':
                    yield self.edbed_clean.put(bed)
                else:
                    yield self.iubed_clean.put(bed)
            else:
                break

    def process(self, pt):
        with self.tg.request() as req:
            yield req
            yield self.env.timeout(10)
        if self.edbed_clean.items == [] and self.bed_dirty.items != []:
            Pre_define.ed_bed_cleaning_request = True
            self.env.process(self.clean_beds_process(pt))                 # =========> This part I use env.process() for call cleaner
        elif self.edbed_clean.items == [] and self.bed_dirty.items == []:
            self.env.process(self.clean_beds_process(pt))
            Pre_define.ed_bed_cleaning_request = True
        else:
            Pre_define.ed_bed_cleaning_request = True
        edbed = yield self.edbed_clean.get()
        pt.edbed_name = edbed
        pt.admin_decision()
        if pt.admission_decision != "DIS":
            if self.iubed_clean.items == [] and self.bed_dirty.items != []:
                Pre_define.ed_bed_cleaning_request = False
                self.env.process(self.clean_beds_process(pt))            # =========> This part I use env.process() for call cleaner
            elif self.iubed_clean.items == [] and self.bed_dirty.items == []:
                self.env.process(self.clean_beds_process(pt)) 
                Pre_define.ed_bed_cleaning_request = False
            else:
                Pre_define.ed_bed_cleaning_request = False
            iubed = yield self.iubed_clean.get()
            pt.iubed_name = iubed
            dirty_edbed_name = pt.edbed_name
            yield self.bed_dirty.put(dirty_edbed_name)
            yield self.env.timeout(60)  # IU bed occupied time
            dirty_iubed_name = pt.iubed_name
            yield self.bed_dirty.put(dirty_iubed_name)
        else:
            dirty_bed_name = pt.edbed_name
            yield self.bed_dirty.put(dirty_bed_name)
    def run(self):
        self.env.process(self.generate_beds())
        self.env.process(self.generate_pt_arrivals())
        self.env.run(until = 200)

run_model = Model(0)
run_model.run()

Solution

  • Patients only get clean beds. Both EU and IU beds are being cleaned. Both types of dirty beds are put into one common bed cleaning queue. The cleaners are smart enough to put eu beds in the eu clean bed queue and iu beds into the clean iu bed queue. Also reduced the iu treatment time to get dirty iu beds to show up sooner in the log. Bed is now a class with a id and type. Otherwise this is the same program from a couple of questions ago

    """
        Hospital bed sim 3
        Patient arrives,
        gets trianged,
        gets a clean eu bed from clean eu bed queue
        leaves eu bed which is queued for cleaning beds
        if admitted get iu bed from clean iu bed queue
        gets treated
        leaves, puting the iu bed in the queue for cleaning.
    
        bed cleaners wait for beds to show up in cleaning queue
        both eu and iu beds are in the same queue
        after cleaning a bed it is put into is clean bed queue
        (clean eu beds go to the clean eu queue, clean iu beds go to the clean iu queue)
    
        Programer Michael R. Gibbs
    """
    
    import simpy
    import random
    
    class Pre_Define:
        warmup_period = 1440
        sim_duration = 14400
        number_of_runs = 1 #3
        eu_beds= 77
        iu_beds=50
    
    class Bed():
        """
            Hosptial beds, can have two types emergency (eu) and inpatiient (iu)
        """
        def __init__(self, id, type):
            self.id = id
            self.type = type
    
    class Patients:
        """
            enity model is processing
            uses beds
        """
        def __init__(self, p_id):
            self.id = p_id
            self.bed = None
            self.admission_decision = ""
    
        def admin_decision(self):
            """
                decides if a eu patient becmes a iu patient
            """
            admin_decision_prob = random.uniform(0, 1)
            if admin_decision_prob <= 0.7:
                self.admission_decision = "DIS"
            else:
                self.dmission_decision = "IU"
    
            return self.admission_decision
    
        
    class Model:
        def __init__(self, run_number):
            self.env = simpy.Environment()
            self.pt_ed_q = simpy.Store(self.env )
            self.pt_counter = 0
            self.tg = simpy.Resource(self.env, capacity = 4)
            self.physician = simpy.Resource(self.env, capacity = 4)
            self.iu_bed_clean = simpy.Store(self.env)
            self.eu_bed_clean = simpy.Store(self.env)
            self.bed_dirty = simpy.Store(self.env)
    
            self.run_number = run_number
            
        def generate_beds(self):
            """
                create the clean eu and iu beds
            """
            self.eu_bed_clean.items = [Bed(i+1, "EU") for i in range(Pre_Define.eu_beds)]
            self.iu_bed_clean.items = [Bed(i+1, "IU") for i in range(Pre_Define.iu_beds)]
           
        def generate_pt_arrivals(self):
            while True:
                self.pt_counter += 1
                pt = Patients(self.pt_counter)
                #yield self.env.timeout(1/7)
                yield self.env.timeout(5)
                self.env.process(self.ed_process(pt))
    
        def clean_beds_process(self, cleaner_id):
            """
                contious process for cleaning beds
                feeds off of the dirty bed queue
                if the queue is empty, will wait 
                until a bed is added to the queue.
                Clean beds are returned to the clean bed queue
    
                This process is the cleaner.  
                It one instance of th process is started for each cleaner
    
                both eu and iu dirty beds are put into the same queue fifo
                cleaner puts the clean bed in the right clean bed queue
            """
    
            while True:
    
                # wait untile there is a bed in the dirty bead queue
                bed = yield self.bed_dirty.get()
    
                print(f'{self.env.now:.2f}  cleaner {cleaner_id} has started to clean bed {bed.type} {bed.id}')
    
                # clean bed
                yield self.env.timeout(50)
    
                print(f'{self.env.now:.2f}  cleaner {cleaner_id} has finish cleaning bed {bed.type} {bed.id}')
    
                # put bed in the right clean bed queue base on type, loop to wait for next dirty bead
                if bed.type == 'EU':
                    yield self.eu_bed_clean.put(bed)
                else:
                    yield self.iu_bed_clean.put(bed)
    
    
        def ed_process(self, pt):
            # process for treating a patient
    
            print(f'{self.env.now:.2f}  patient  {pt.id} has arrived')
            with self.tg.request() as req:
                yield req
                triage_service_time = random.expovariate(1.0/18)
                yield self.env.timeout(triage_service_time)
            
            print(f'{self.env.now:.2f}  patient  {pt.id} has been triaged')
            
            # yield self.pt_ed_q.put(Patients.id)
            # pt_id = yield self.pt_ed_q.get()
            # Bed_Mgmt.check_q(pt_id, self.pt_ed_q, self.bed_clean, self.bed_dirty, self.bed_cleaner)
    
            bed = yield self.eu_bed_clean.get()
            pt.bed = bed
            print(f'{self.env.now:.2f}  patient {pt.id} has a clean bed {bed.type} {bed.id}')
    
            with self.physician.request() as req:
                yield req
                yield self.env.timeout(10)
                pt.admin_decision()
    
                print(f'{self.env.now:.2f}  patient {pt.id} has admission descesion of  {pt.admission_decision}')
                
    
            if pt.admission_decision == "DIS":
                # get iu bed
                bed = yield self.iu_bed_clean.get()
                
                # move patient to new bed
                yield self.bed_dirty.put(pt.bed)
                print(f'{self.env.now:.2f}  patient {pt.id} moved to IU giving up bed {pt.bed.type} {pt.bed.id} and taking bed {bed.type} {bed.id}')
                pt.bed = bed
               
                 # time until IU bed becomes becone available 
                yield self.env.timeout(60)
                yield self.bed_dirty.put(pt.bed)
                print(f'{self.env.now:.2f}  patient {pt.id} left IU giving up bed {pt.bed.type} {pt.bed.id}')
            else:
                # patient leaves hospital
                yield self.bed_dirty.put(pt.bed)
                print(f'{self.env.now:.2f}  patient {pt.id} left EU giving up bed {pt.bed.type} {pt.bed.id}')
    
    
        def run(self):
            self.env.process(self.generate_pt_arrivals())
            self.generate_beds()
    
            # creating and starting two cleaners
            for i in range(2):
                self.env.process(self.clean_beds_process(i+1))
            
            #self.env.run(until = Pre_Define.warmup_period + Pre_Define.sim_duration)
            self.env.run(until = 650)
    
    for run in range(Pre_Define.number_of_runs):
        run_model = Model(run)
        run_model.run()
        print()