Patient pile up at reception

[santiagodiazames]

[ FlexSim 23.2.3 ]

There's a pile-up of patients at the reception area by end of day in my simulation.

GROUP POD - Scenario 00_12 JK.fsm

I can't figure out why this is happening.

I have a statistics collector called Care Vs Time.
When I analyze its output, I see the overlapping MD Exam and Charting actions for the same doctor (see between 11:00 am and 12:00 noon):

Morning:

Afternoon:

81 patients were scheduled to arrive in one day.
According to the data output, 81 patients are examined.
Therefore there shouldn't be a pile-up of patients by the end of day.
Would anyone be able to take a look at my model and see what might be wrong, please?

[Jeanette_Fullmer · Accepted solution]

Hello @Santi

You have patients acquire the MD and then assign them exam beds that are not available. So, there is a buildup that cannot move. Why do you select Exam tables with the custom code first?

[santiagodiazames]

Hi Jeanette,

I didn't do that part of the Process Flow. But I'll try to get an answer for you.

I think that the data I showed from the Care Vs Time statistics collector only goes up to 12:00. The rest must be data left over in the Excel spreadsheet from the previous time it was exported to Excel. That explains the overlapping activities.

Here are some additional observations that may be of use:

There are idle MDs and MAs, while patients are waiting for them:

• At 10:37:30 MA1_6 finishes setting up Exam Table 2. From this point forward, MA1_6 stands idle at Exam Table 2 for the rest of the day.
• At 10:54 am MA1_5 stands idle at Desk 1 for the rest of the day.
• At 10:54 am MD1_2 is idle at his desk, while MA1_2 stands idle next to him, both idle for the rest of the day.

By 11:05 am, 1 MD and 4 MAs are permanently idle, while several patients are waiting for these idle staff members.

By 12:00 noon, all MDs and MAs are idle for the rest of the day.

[moehlmann_fe]

There's a possible deadlock build into the main Patient Flow. The MA is released during the examination but must later be reacquired before the exam table is released. The waiting patients first acquire the MA and then the bed, so the tokens waiting at the start and after the exam are blocking each other from progressing since they each have acquired something the others need.

In this case this can be prevented by having the waiting patients first acquire the exam table and then the MA.

[santiagodiazames]

Hi Jeanette and Felix,

We want a medical assistant and an exam room to be assigned to a doctor.
This way, the doctor can only use pre-determined exam rooms, and can only be assisted by pre-determined medical assistants. There are 4 doctors, 6 medical assistants, and 10 exam rooms (exam tables). Therefore while the first 4 medical assistants are assigned each to a doctor, the remaining 2 medical assistants are shared amongst each pair of doctors. A similar logic applies to which exam rooms (exam tables) each doctor and medical assistant can work in.

I've attached a PDF that describes the logic of the assignment of medical assistants and exam rooms. BA FlexSim organizational structure (Jan 17, 2024).pdf

This might not directly answer your question, Jeanette.
But it explains the original intent behind using custom code to select exam tables.
Would you have achieved the same objective with a different approach?

[santiagodiazames]

Hi again. After extensively analyzing the model in great detail, I've found some specific issues with the process flow.
I'll accept this post as the answer for this topic. And I'll create new posts for each specific issue that I'm not able to solve on my own.

Thanks again @Jeanette F and @Felix Möhlmann for your insights. This is much appreciated.

Santi