Reusing: Nonelective Flow DES

Model overview

The Non-Elective Flow Simulation is an open-source discrete-event simulation developed by Helena Robinson at Countess of Chester Hospital NHS Foundation Trust. It represents patients moving from the emergency department into SDEC or an inpatient bed and explores how bed capacity, admitted length of stay and SDEC activity affect queues and waiting times. The model is written in Python using SimPy and includes a Streamlit interface.

Registration for this cycle is now closed. Please check back for future cycles.

All sessions

• Cycle 1: Running Non-Elective Flow DES
• Cycle 1: Reusing Non-Elective Flow DES
• Cycle 2: Running NHS 111 primary care DES
• Cycle 2: Reusing NHS 111 primary care DES
• Cycle 3: Running triage during intense COVID-19 demand
• Cycle 3: Reusing triage during intense COVID-19 demand

Actions for participants before the session

In order to reuse a model you need to understand its structure and implementation. Prior to the session participants will:

• describe how they think the model is structured from inputs through to outputs;
• compare that understanding with the repository and SimPy implementation;
• identify how patients, queues, resources and events are represented;
• locate assumptions for arrivals, length of stay, capacity and SDEC activity;
• discuss what they would change for a different question, service or local setting;
• attempt to make a change to the model and run it successfully;
• consider how a change would need to be tested, validated and documented.

The aim is for participants to be able to identify a model component that they would change, locate it in the model and assess whether they understand the implementation well enough to make the change confidently.

Session objectives and outline

This session will focus on discussing how participants experienced reusing the model. Participants will:

• share their experience of modifying the model for their own needs;
• discuss any issues they encountered and how they resolved them;
• reflect on what they learned from attempting to reuse the model.

Additional resources

• GitHub repository — source code and repository documentation.
• Project presentation slides — background to the model and its intended use.
• HSMA showcase presentation — recorded project presentation.
• Vidigi paper — related work on animated visualisation of discrete-event simulation models, using this model as an application example.

The project is documented through its repository and HSMA materials. We are not currently aware of a dedicated peer-reviewed paper or independent reproduction of this specific model.