Health and Care Simulation Community of Practice

Our HaC S CoP was established to provide support applying system dynamics to real world problems. It provides a space to share information, ideas and resources as well as seek advice and guidance from community members.

Welcome to the Health and Care Simulation Community of Practice (HaC S CoP).

If you work in health and care in the Midlands or beyond and are interested in using simulation techniques, then the HaC S CoP is for you!

Currently we focus on System Dynamics but we hope to expand to cover other methods if there is sufficient demand.

Our HaC S CoP is a growing community of practice from a range of health and care and related organisations.  Established in April 2023, to provide support in applying system dynamics to real world problems, it provides a space to share information, ideas and resources, as well as seek advice and guidance from one another.

Our Community of Practice Host / Advocate is Stacey Croft, supported by Sally Thompson

Stacey is an Analytics Manager at the Strategy Unit whose focus is on simulation methods. Using these methods in a participative way to enable organisations to explore different ‘what if’ scenarios, to understand the impact of proposed changes to services to make better-informed decisions. She is working to grow the System Dynamics community in the Midlands and beyond and to broaden the scope of the Simulation Community of Practice.

Activities of the HaC S CoP:

We have a range of activities, shaped by the community for the community.

  • Mid-Month Catch Ups – We meet virtually via Teams every month, on the afternoon of the third Thursday of the month.
  • Advice clinics – These are private bookable sessions for support to Midlands participants to help progress their new or ongoing projects. These provide mentoring time from Douglas McKelvie, a leading expert on System Dynamics in health and care, Stacey Croft, Simulation Analytics Manager and Sally Thompson, Senior Healthcare Analyst specialising in System Dynamics.
  • ‘Fish bowl’ sessions – These are bookable sessions for support to those in the HaC S CoP (including outside the Midlands) to help progress their new or ongoing projects. These sessions are open to the wider group to attend, so that they can learn from the advice and examples, and help to prevent duplication of work as many may also tackle similar problems. These provide mentoring time from Douglas McKelvie, Stacey Croft or Sally Thompson.
  • Training, networking and shared learning events – We have some online learning sessions, and we recently had an in-person event in Birmingham on March 7th
  • Developing local projects for wider use –  As part of our support to the CoP we will look for projects that may be suitable for development to use beyond their original organisation(s) and look to share these for wider use.
  • Encouraging national spread and support – We very much support all those who want to further their experience and network with peers outside the Midlands.  All those with an interest are welcome to attend and present at the monthly catch-ups, fish bowls and learning events.

We also recently completed a 6 month Midlands System Dynamics Applied Learning Programme for analysts to create analytical capability, within ICSs and local health and care systems, to use SD to address problems in their systems. There was a whole range of problems addressed including mental health bed capacity, future demand and supply of care homes places, colorectal 2 week cancer waits, dermatology outpatients, stroke pathway, end of life care, hypertension and Improving Access to Psychological Therapies (IAPT). A video presentation on this training is in the ‘useful resources’ section below.

Why use System Dynamics

The challenges that the NHS face are increasingly complex, transitioning from services and organisations to local system level strategic planning. Using System Dynamics we can simulate ‘what if’ scenarios of different policies, interventions, changing resources or capacity on behaviour across the system, helping to facilitate conversations and aid decision-makers to make more informed choices. System Dynamics provides the opportunity to take a system view and incorporate population health and needs prediction, to underpin medium and long-term strategic resources (including workforce) planning.  It also provides evidence-based decision making for the re-allocation of capacity within a system and new ways of care delivery.

What is System Dynamics

System Dynamics is a simulation modelling technique. Modelling the behaviour of complex systems and their interconnections over time as continuous flows. System Dynamics models are capable of exploring feedback loops and interactions between factors over time. This allows the identification of both intended and unintended consequences, building a greater understanding of system behaviour.

These models are built with:

Stocks: where the flow accumulates or depletes over time e.g. patients undergoing treatment, patients waiting

Flows: in and out of stocks, resulting in the changing level of the stock

Auxiliary variables: Explanatory and soft factors which influence them.

Using these stocks and flows we can represent patient pathways. Fundamental to understanding patient pathways such as the example below. It relates people waiting, referrals, admissions, bed capacity, bed occupancy, length of stay and discharges. Using this structure we can understand how these variables are linked together and dispel common mis-conceptions about the impact of strategies and facilitate discussions on how they work.

Simple service with capacity constraint

In the example, each month a number of people are referred to a service. They join a ‘waiting list’ (a stock) until there is spare capacity within the service. This is determined by considering the capacity, the number of service users and the number of people finishing the service. Once there are spare places they flow from the ‘waiting list’ stock into the ‘service users’ stock. People receive the service for a certain average duration after which their service ends and they flow out of the ‘service users’ stock. If the number of people joining the waiting list each month is higher than the number of people ending the service, then the waiting list will rise.

However, simulation modelling is not just an analytical method, it requires wider skills such as facilitation and a collaborative approach. Simulation is a learning tool, it improves the collective understanding of how a particular system ‘works’ through engagement, learning, feedback and therefore iteration between stakeholders and the model is a vital process.

Those seeking insight learn not only from the final model but by the process of building models through a participative approach. Mixed groups of stakeholders collaborate to explore mapping the main aspects of the system, how the system works, its main constraints and dynamic impacts, current challenges, future policy and possibilities.

Useful Resources:

1.Examples of System Dynamics models in health and care:

2. Useful texts:

3. Groups active in system dynamics in health and care:

HACA: Presentation on the Midlands System Dynamics Applied Learning Programme

This video is a presentation on the System Dynamics applied learning programme in the Midlands that we ran between September 2022 and March 2023.

For more information or to join the community please contact your Community of Practice Host and Advocate

Stacey Croft ( or

Sally Thompson (